But since it seems to be broken, using its descriptive features as final effects seems inappropriate.
What exactly is broken about it?
I'm a bit confused on how exactly are you going to do your own version of bg2 with the kind of changes you've posted so far, as these kind of racial bonus change aren't going to change the gameplay story wise at all and combat wise hardly at all, as irrelevant as my opinion on that is.
I rather talk about why you want to do these changes to the game, and why you probably shouldn't do them.
1. The current racial statistics in the game are quite unimportant to the gameplay you might think, besides the races restricting class choice and dual/multiclassing. But the +1/-1 stats and especially the saving throw differences are almost as relevant to gameplay as the bonuses you suggest for the races. So changing them to the ones you suggest would not make much sense, especially when they have nothing to do with the ad&d rules. For example dwarfs, halflings and gnomes are overpowered i'd say as they are because of their saving throw bonuses, as +2 to save vs spells pretty much translates straight to 10% mr against most spells. So if you know how big their saving throw bonuses are compared to humans, orcs .etc, you realize how big of an advantage they have, orc for example is a horrible race with its +1 to str and con, but humans have dual classing which can be very powerful, and the races which get the big saving throw bonuses are quite class restricted.
So the game does have quite good balance because of the class restrictions of the races, the little folk suit fighter/thief classes the best, but can't be arcane casters, except gnomes, but they have the con of not having necromancy school available which has many important spells.
So i hope you realize now that the race stats that are in place now, and the ones you're planning are just as gameplay relevant, but the ones you're planning to implement are more unbalanced, the regen of the dwarf is way too op for early game, the dmg bonus of the orc is way too op at any time, the half-elf bonuses just doesn't make any sense and are op early game, halfling op late game, gnome op. My opinion on their balance is only if we are still playing the same game, as if the enemies are the same as in vanilla bg2.
Like the others said, most of these stats will only affect fighter type characters, so they will be even less relevant than current bonuses for casters. Another reason why i think you shouldn't do these changes is the effort it will take you to do them, and also because if you don't do the changes to enemies in the game, they are going to have even less impact on gameplay, and if you will give them to enemies aswell, it will just mean more effort for you.
2. The defense system you have in mind is like the one in fallout 1/2, and implementing it would be extremely hard because the current AC/defense system is hardcoded.
Putting aside the difficulty part of implementing it, i think its completely pointless aswell. Mostly because the current defense system works just fine, and has very little difference to what you're suggesting, as its 5% per to hitting chance per AC or THAC0 point.
The balancing of AC is just quite bad in the game for enemies in a way. Early SoA its quite well balanced, but the further you get it becomes easier and easier to hit enemies. Like fighter classes can hit enemies mid SoA(not counting dragons) to late ToB pretty much with a 95% chance, but if you'd play a solo class thief for example, you'd have much bigger difficulty, same for bards, so its not as badly balanced as people might think. Personally i'd tweak enemy AC higher, because most of the time when you play a chr that needs to hit enemies with a weapon, its a class or class combo that is well suited for doing that, and those classes have too easy time hitting monsters late game, although i'd tweak thief and bard THAC0 a little higher then prolly.
The AC of the player is quite balanced imo, for fighters chrs again its extremely easy to hit AC in SoA where the chance of getting hit is only 5%, only exceptions being dragons, Iron/Ada golems, a few demons and a few high lvl fighters. In ToB most people seem to think that AC for players is quite useless from what i've seen, i don't share that opinion to quite the same extent. AC in ToB is completely useless if you're below -15, above -20 its good for normal mobs, but against bosses you need more, but its possible to acquire AC so high that even the bosses with the highest THAC0 will miss most of the time. Its just very easy to forget that when surrounded by 10 glabrezus for example, even if they only have a 5% chance of hitting you with a critical hit, so you're probably going to get hit a couple of times in a round if there is that many enemies hitting you cause of critical hits, so resistance is useful especially in such occasions, but against a single or a few strong mobs high AC can be very useful, but the more attacks per rounds against AC, the less effective it becomes you could say, cause crits are a bitch.
Okay so i'd suggest if you want to make changes to the races, keep the original stats of the races that people are used to, then either add balanced stats, or rather give the races new inniate abilities. I think new abilities would interest people to make a choice between races more than stat changes, and imo usable abilities are always more fun than static stats. If you want to tweak stats in general, then i'd start from wisdom, intelligence, and charisma, as those 3 stats have very little effect to gameplay for most classes, and charisma has next to no effect to anything, but it should really only affect dialogue options which is why its such a hard stat to make use of.
If you're serious on changing the entire game, then stop thinking small scale changes like these and asking if they are balanced for the vanilla game, cause if you're going all out and changing the games story and/or tweak the combat system over, then its not relevant what is balanced for the vanilla game.
Personally i'm quite suprised you want to remake bg2 and the ad&d system, when you don't seem to be very familiar with either of them, and thus can't probably fully appreciate them, but by all means don't let that limit your vision on what you want to do.