If I make a edit to RCS do I have to copy and paste every time into RSD or FF to update the html and body or can I keep the same slideshow name and just upload the edited RCS file ? I have to use slides alot and sometimes may need to just edit one slide.

you won't need to alter the reference to the cc-slideshow in the site header, just the html bit and possibly the .css in resources (assuming there has been changes made to that file whilst editing, although I find it just a quick and easy to do the whole lot, once finished editing, (and I also do a lot of changes to RCS slides, tried it both ways, not that much difference in time and effort really.)