There is no difference between the free and the pay-versions afaik.
FTP and CVS are usefull add-ins, but they're not really neccesary. I don't have them (got no money

), but if you can afford them they can be very usefull. FTP makes it possible to edit files directly on the server (without having to download and upload them yourself).
CVS is for when you work on a project with multiple people. It's hard to explain, but google it, and you'll find out what it is.