I'm unsure if a bad ball joint would cause negative camber; hopefully someone else will jump in here. You can do the suspension work yourself (but you'll need to find someone with the proper press to do the BJs). It is pretty straightforward if you've got sufficient tools and the manual but can involve lots of effort and foul language to get things apart, especially if they salt the roads where you live. Here is a pretty good writeup of what is involved.

Tom