From what I saw, solo is a lot easier than coop (streams of the game, not played it myself yet). Enemies have basically no HP, and you can predict what they do, just like in a normal Souls game. Also, you're not getting matched with randoms.
If you're playing with friends, sit in voice chat, that might get easier for you again.
Unless you're making some Nvidia = green joke, that's some setting on your side. The crashes might be as well, some unstable overclock or PSU issue.
The main things that's been plaguing the Nvidia drivers is black screens, which are seemingly finally getting under control for the last two driver releases, along with Windows Updates.
Value of the 50-series is definitely shit though.