Veteran D&D player here, and veteran BG 1/2 player, but not a D:OS player.
4. I've long used advanced humanoid enemies. Bog standard enemies out of the book get boring after a while. I cut my teeth on 3E, so the idea of NPC classes (adept for spellcasters, warrior for combatants) makes perfect sense for me. They create dynamic fights. The PCs are special, they don't have to be the only Wizard in the world to be special.
I want to address this one in particular because my own campaigns heavily feature advanced humanoid enemies as well. I think it works well in a face to face setting where I can dynamically adjust the strength of the NPC enemies up or down, but the current iteration computer DM is relentless. When you have a party crushing DM and give them a bunch of additional goodies on top of this it can stop being fun VERY quickly. I'm looking at the Gnolls and seemingly endless Cleric enemies
Which I can forgive because THE ABSOLUTE and all
in general here honestly. That heat map of deaths Larian posted feels like it may be weighed more in favor of these special humanoids because of it and the completely garfunkled action economy/CR imbalances.
On the other hand, the players also have this problem though where there is an over saturation of items and scrolls that do roughly what every other party member can or can't. Having all of your weaknesses shored up is great, good. I love it from a design philosophy. But not here, if that makes sense. You can be accessible without being heavy handed or sacrificing the flavor of the setting.
