We're deep at receiver so I have no problem with Gaffney returning punts. I do have a couple of issues with Hollings returning kicks, though: he's very valuable to us as a RB right now (even more so with DD apparently nursing an injury), and we need to see how he holds onto the ball in the rest of the preseason games. His own injury recovery has to be watched, too.
Too early to answer question 1. As for question 2, I see Carlton Thompson's point--if you're going to use a roster spot on a specialist, it better be a great one. But is it really THAT limited, to where only someone as good as Dante Hall merits that spot? I don't like the idea of writing off the return game like it doesn't matter. It DOES matter.