There are a lot of issues with the game but nothing of what you are talking about is true.
Melee combat is OP right now. My paladin can one shot almost everything and takes no damage from missiles.
Dice rolls are random. If you’re getting a lot of 1 rolls and 20 rolls then that is just your own personal luck.
Reactions are attacks of opertunity and they exist in the game.
The story is much better than BG 1 or 2. Maybe you’re thinking of Planescape. Then you would be correct.