From what I've found so far, Quicktime is it. That's all you enable/disable with the Plug-Ins option, nothing more. Flash is not supported at this time, as you've discovered, so any flash sites or applications most definitely will not work if you browse to them, and disabling the Plug-Ins option should stop any Quicktime videos from playing/caching on websites. If I manage to find any more info, I'll post it up, but so far, that looks to be the only thing enabled/disabled.