Yes, we have a feature called 'History' which you can access from the editor. It lets you see the changes that have been made to your project over time. It's a bit of minimum-viable-feature at the moment, but it's still quite useful, and we're always open to feedback on how to improve it for your needs.

You should think of including support for latexdiff (http://www.ctan.org/pkg/latexdiff). People will love that I believe.

Yes, we'd love to do that. I coded up a prototype a while ago and found that latexdiff can quite easily get confused and produce LaTeX code that won't compile. I definitely plan to revisit this though and try to get something working.