I started a no-XP game of my own just to see what it would be like. It's certainly...different from what I'm used to. I believe in 100% completion and helping everyone who needs aid, and fighting my own instincts is a challenge.
Even so, I'm off to a pretty good start. I'm doing things differently than you are, SSoG/Warlock/NeoWarlock.
For one thing, I'm trying to do as many things as I can. For example, I'm acquiring every item I can. I also seem to be following different guidelines than you are. I'm not trying to solo the game, so I intend to use any NPC at my disposal if I need their help. I'm being schizophrenic when it comes to cheese and game exploits. For example, when I steal from a merchant, I don't sell his own wares back to him, and I don't sell him the same stolen goods more than once. On the other hand, I have exploited a bug in the game that lets Yoshimo set an infinite number of traps---so much for realism. I won't be using that trick anymore since I'm ready to go to Spellhold and I'm finished with Yoshimo. I also cheated in a Bag of Holding to make shoplifting easier.
I'm playing Shadows of Amn (no TOB) with the official patch, the Baldurdash FixPack, and a few components from the Ease-of-Use mod such as infinite stacking. I'm playing on the Core Rules setting. My character is a gnomish Illusionist/Thief who started with 161,000 XP. Her stats are 15, 18, 16, 19, 3, 18. She started with 90 thieving points in Hide in Shadows, 90 in Move Silently, 60 in Detect Illusion, and the rest in Find Traps (I can't remember the exact number). I don't think I'll be putting any points in Open Locks, Pickpocket, or Set Traps. Her spellbook has five 1st Level spells (Magic Missile, Spook, Reflected Image, Chromatic Orb, Identify), five 2nd Level Spells (Mirror Image, Resist Fear, Glitterdust, Stinking Cloud, Knock), five 3rd Level spells (Spell Thrust, Flame Arrow, Hold Person, Invisibility 10' Radius, Slow), and five 4th Level spells (Emotion, Stoneskin, Greater Malison, Secret Word, Improved Invisibility). I plan to use all the potions, scrolls, and wands at my disposal. The truth is, this character can kick some serious ass in Chapter Two (as long as you're not talking about dragons and the Twisted Rune and so forth) even though I'm trying not to kill anyone. Maybe starting with 161,000 XP was a mistake, but I'm not sure how things will go in later chapters.
In Chapter One, I didn't think that pickpocketing the Sewage Golem was necessary since I could have snuck past the goblins and grabbed the Activation Stone, but I pickpocketed the key from him anyway. I told Aataqah and Rielev I didn't have time to talk. I looted as much of the dungeon as I could. I even grabbed a bunch of stuff right in front of Illyich and then ran and hid in the shadows before his group could hurt me very much. Mirror Image is always useful for evading traps, and Knock allows me to open locks without getting any XP. The mephits were the only monsters I had to kill. Imoen used all of her summoning spells to get some worgs on our side. I got five of the wands that are converted from keys (I pickpocketed one of the keys from the Escaped Clone) as well as the stuff in Frenneden's room (I slammed the door shut and hid in shadows before he could follow me), the Ring of Protection +1, and the Girdle of Bluntness.
When I emerged from Irenicus's dungeon and watched the cutscene, I got some unavoidable experience. I sold some items to raise some gold (about 1100) and proceeded to meet Gaelan. Then I went upstairs and bought a couple of Potions of Master Thievery, then I left and did some shoplifting around Athkatla. Along the way, I pickpocketed the Ring of Regeneration from Ribald and the Ring of the Ram from Tolgerias. I tried to pickpocket the Tuigan Bow from the beastmaster at the Copper Coronet, but it couldn't be pickpocketed (I got the key to Hendak's cell, so I unlocked it without talking to him). When the first round of potions wore off, I went hunting for some more items.
I looted the Graveyard, which wasn't easy. I had about twelve monsters following me around, including the Crypt King, and I had to use a couple of potions of invisibility to elude them. (I ditched most of them inside some rooms I had already looted.) I'd like to go to the lower tombs (where Edwin finds his Nether Scroll) and get the Wand of Paralyzation, but I didn't feel like dealing with all of the traps and monsters.
On my next round of shoplifting, I collected about 120,000 gold pieces. When I went to see Roger in the Temple district sewers, I pickpocketed some items from Tarnor the Hatchetman before paying the toll, and I got the Rod of Resurrection from Mekrath's lair. I tried to pickpocket the Boots of Speed from Renal, but it didn't work. I told him I would work for him (I lied), which got me access to Mae'Var's guild. I killed Mae'Var with Yoshimo's traps without getting any experience and freed the guy who'd been in a cell for ten years. Strangely enough, no one else in the guild became hostile.
I pulled the same trick on Mencar Pebblecrusher and his gang and killed all of them except for Pookie. Every time I dismissed Yoshimo, I told him to wait right where he was. When I accepted him back into the party, his traps were refreshed. Voila, infinite traps, and no XP for me if he wasn't in my party when his traps killed our enemies. Definitely a bad bug, but I used it.
I met Delon in the Government District and told him I would accept his quest (I lied) so I could go to Umar Hills. I had the Bronze Horn of Valhalla, and I wanted to get the beljuril gem from the chicken so I could upgrade the horn. I also wanted to see if I could visit the Shade Lord's dungeon to pick up a few interesting items, but I abandoned that plan when I found out that reading Merella's Journal or the Note from Mazzy Fentan gives you 22,500 XP.
I bought a few nice items including the Robe of Vecna, a Wand of Fire, a Wand of Monster Summoning, the Girdle of Hill Giant Strength, Bracers of Defense AC 3, Aeger's Hide, Dak'kon's Zerth Blade, and Kachiko's Wakizashi, and I had stolen a bunch of others such as Short Bow +2, magical arrows, and the Nymph's Cloak. I recharged two of the wands I had gotten in Irenicus's dungeon (the Wand of Fire and the Wand of Monster Summoning). I even picked up Daystar in the City Gates area. (I ran out the room while the lich was casting a spell, so he couldn't follow me.) I had tons of potions and scrolls when I was ready to start Chapter Three.
I sided with Bodhi. It wasn't exactly a cakewalk, but I got a minimal amount of experience. The first assignment was to intercept a shipment at the docks. I cast Emotion to put the poisoned dart throwers out of commission, and I charmed Mook and pickpocketed the smuggled goods. I could have sent her back among the other Shadow Thieves to let them kill her, but I was merciful--I took her to the other side of the Docks District and left her there. I got zero XP until I returned to Bodhi.
Before I went back to her, I snuck into the Shadow Thief Guild Hall and had Yoshimo set a bunch of traps where the next group of Shadow Thieves would spawn during the next mission. Infinite traps exploit and meta-gaming--you gotta love it. I came back to that room after Bodhi gave me the next assignment, and it worked even better than I had hoped. I went back without Yoshimo and his traps killed six thieves instantly, leaving only one spellcaster whom I had to kill for 3000 XP. Then I returned to Bodhi for my final assignment--kill Aran Linvail.
I had to get a key from Gaelan. It can't be pickpocketed; you have to take it from his corpse. But I figured out a way to kill him without getting any XP. I lured some thugs into Gaelan's house (the ones who attack you in front of the Copper Coronet) and charmed Gaelan, and he was attacked and killed by the thugs. I picked up the key and left.
Getting to Aran mostly involved sneaking around a lot. I pulled the lever to open one of the doors (getting 17,500 XP in the process). I knew how to get the key from Haz without killing him myself--I charmed him and let the other thieves kill him for me. With the key in hand, I made it to Aran's chamber. I almost got stuck because a thief was blocking a door, but I used the Ring of the Ram to clear the way.
Killing Aran was fairly difficult since I didn't want to kill anyone else. There was a Mage in the room who cast True Seeing, but fortunately Yoshimo was wearing the Cloak of Non-Detection. I knocked out a couple of the Shadow Thieves with an Emotion spell and cast Hold Person on a couple of others. Aran summoned a Nabassu with a Gate spell that appeared out in the hallway and it couldn't get through the door. Fortunately, the Mage I mentioned earlier was standing right next to the door and he and the Nabassu attacked each other. I had trouble with Aran's Mislead and Invisibility spells (my thief skill Detect Illusions didn't seem to be working), so I had to wait for them to wear off. In the meantime, I summoned some ogres with the Wand of Monster Summoning to keep him occupied. Yoshimo was hit by some kind of fear spell so he was out of the action. Aran managed to kill the ogres, so I summoned some gnoll elites who fared a lot better. When Aran went down, I looted his corpse and stuck around a little while to keep the gnolls from attacking everyone else. I was afraid they were going to kill every enemy in the room. When the Hold spells wore off, the tide turned against the gnolls, so I abandoned them and left the room. The Nabassu followed me but then got sidetracked by the Air Elemental, and they started duking it out. I gulped a Potion of Master Thievery and pickpocketed a key from Booter the torturer and freed Tizzak (I think that was no XP) and then I was out of there.
That's where things stand now. I'm trying to decide whether I should take an NPC with me to Spellhold. (It won't be Yoshimo.)