Well myself I didn't notice more critters but just that totally similar beginning generate rather different effects in same fights, I'm almost sure that some fight computing are changed.
The changes are far to be as limited than those you quote, you probably never played the original BG1 or forget it. Here few examples :
- Classes are BG2 classes and not BG1 classes, not necessary a good point for BG1 low level characters and BG1 items available.
- For example, a weak design point of BG2 is that there's too many weapons specializations but this weak design becomes a very poor design with BG1 low level characters and BG1 more limited choices of special weapons.
- NPC are changed a little, even when you request their base class design. For example with Tutu Kagain is specialized in 2 weapons and is trained only in Axes.
- The walk speed is faster, that's a clear rule change in fights.
- Walk speed can vary for some characters, they can be faster (and perhaps slower). For example my character was a lot faster than all companions. When in BG1 they all have the same walk speed and I never enjoyed the effect in BG2 of having one character rushing far ahead and a bit isolated if a fight starts.
- Default stack arrows are bigger in fact only some BG1 stacks are as big but not all, for example stack arrows are 40 when in BG1 it's 20 and only some are 40.
- Also Tutu includes the whole pack of DudleyFix. But this pack isn't only pure fixes but also changes that fans whose made the pack think as inconsistent. Well that's the point of view of hardcore fans not of game designers, and even if most changes seems quite logical you could still wonder if they was really required. Let get an example, Lay on Hand should now bypass resistance because it's the standard rule… but well I consider this rule as a weak design.