Reply to the first post, I think that it can be done, the reason that I say think, is that I jammed my WRX into first on a turn at an autox a few weeks back after I screwed up the turn and approach. With all the adrenaline pumping and a huge 'sorry' to my car, I coerced my baby into first gear and it was not happy about it. I didn't even look to see how fast I was going, nor the rpms, but it is not something that I would suggest for normal operation, or doing it unless you actually had to. I know that the car was still moving semi-quickly, however the wrong direction, but when I shifted and hit the gas again, I was high enough in first to take off like a rocket and had to shift again real quick.
so, yes, it can be done, no, I would not reccomend doing it.
As for the stop and go, there are some times where you need to downshift to first, but I would wait to shift until the mph is pretty low.