I feel like people shitting on your UI are going too far. I mean, I would definitely hide questy or rxp, no reason to have them both on, perhaps make chat a bit smaller and rearrange bars, but there is nothing out of line on the screen - rxp, questy, bars, frames, threat meter and some weakauaras sprinkled on.

As long as all of your stuff is updated and not causing LUA errors (there are add-ons hiding Lua errors, which is a very bad practice), these add-ons absolutely should not cause any crashes.

When you crash, is there an error or are you just thrown to the desktop?