I mean, welcome to DnD--where RNGesus can sometimes royally screw you over and you have to live with the consequences. Difference is, in the game you can reload. Can't do that with tabletop.
Anyway, to address your "issues"
1. Fights that start from conversations gone bad mean you probably borked a skillcheck. You DO have ways to prepare before a conversation if you have a spellcaster. Use them! If you don't have the right spells prepared, well...that's DnD.
2. Addressed in 1, there are preparation spells. It's not Larian's fault if you decided not to run with a support role like a cleric.
3. Dying is part of the game as it is part of DnD. Be glad your character doesn't have perma-death. Sometimes the dice just don't roll your way. Reload and try again.
4. I've had no problem with the early game. Maybe you're trying to advance too fast. Player level is important, far more in DnD than most other games.
