You might be expecting more direct collaboration than Fedwiki seems to be designed for. Forums are better for discussion. Blogs are better for sharing an essay and getting feedback. Google docs are better for small-group projects. Traditional wiki is better for public collaboration aiming for consensus.
Fedwiki seems best for individuals to share ideas divided into short pieces. I’d like to see it used, for example, by various individuals sharing their personal notes, with their best efforts to arrange and explain math, programming, and science concepts. Forking isn’t even necessary, since you can simply copy, imitate, or adapt the efforts that appeal to you. I’d prefer to see pages remain more or less individual. I don’t care what changes someone makes to my pages, or whether they use changes I’ve made to their pages.
If I understand (and that’s a big “if” at this point), finding someone else’s edits to a page should just require making sure they are in your neighborhood, then visiting the page. Newer (or older) versions by anyone in your neighborhood should be available via the little squares at the top of the page. (At least that’s the way I think it’s supposed to work. I haven’t tried it much yet.)