Cheese does not bother me as long as the gameplay and difficulty is not built around it. I never used and use barrels, I never hide chars in combat (except Astarion who is seldomly in my party), I don't use scrolls, or much shoving (4 times till lvl 5 in my current campaign). I don't care about jumping, but I would be entirely ok if "move distance + jump distance = move distance".
But stealth, or more generally the reaction of enemies to attacks, indeed is problematic. Surprise attacks from stealth are almost always a natural option if NPCs are known as enemies before the fight (therefore I never start the Gith fight other than from the dialog), so you have to deal with it all the time, it's omnipresent, and has to be right. Set bugs apart (several enemies in my current playthrough did not react at all, standing just around), there should be some changes. Some ideas in the thread sound nice, in the doubtful case I really did understand them.
My homebrew thoughts (I'm not a DnD guy) are more or less:
Stealth should be mainly for rogues and alike, the other classes shouldn't be able to use it once in combat. When starting combat you should have different possibilities. If the party is close together, to make it easy to decide, all members should be in combat and out of stealth if an NPC is hit, and able to attack with advantage in their normal turn; no double attacks but they should go first all in initiative. If they are further afar and not immediately in combat (that should be possible), so they cannot "shoot together" and have to move, they should have a stealth check but never be able to attack with advantage, stealthed or not (the person hit knows that heroes always travel in packs and expects more attacks to come, as do his/her companions).
