How can I edit translated video on a Mac?
I use SubMerge to load and sync subtitles to movies. I generally look for subtitles in SRT format. You can usually edit the subtitles texts inserting (or removing), pauses or blanks. A difficult part is that it's not uncommon for subtitles to slowly get out of sync with the film as the latter progresses. Adding - or removing text is really handy to restore synchronization. It is a bit of a laborious process though :)

Once I have the stuff in sync, then I too use Handbrake to change formats if necessary. Hope this helps.