Yes, if you save an edited post, there will be an edit history that you can view and restore if you need to. It'll appear on the bottom of the content near the 'Delete', 'Edit', and 'Report' buttons.
RpNation
Chordling
CharityCase
Can other people see it...? I'm gonna be honest, I woke up at like, the butt crack of dawn, wrote a reply that was total garbage, went back to bed, woke up at a more reasonable time, realized I'd written total cringe, edited the reply down to a generic placeholder, and am now wondering if my poor, innocent rolepartner can see the nightmare of what I had originally left them