Scenario A:
I would generally watch the episode to the end, much like in a TV. And then I would rewind it. Because then, I could rewind it several times more, just to enjoy the glory of given moment. Especially if there are more than just one moment. Otherwise you might just end up re-watching same fragment(s) for who-knows how long without actually getting on with the episode...and sometimes, I think that the "flow" of the episode can really get crashed by suddenly pausing and rewinding. At least, that's what I feel.
Scenario B:
Generally no, unless it could have plot relevance.