Ok, so I got my GTD in March - loving my car

but I have a couple of queries;
The auto handbreak.. Sometimes it will auto release when i go to move off, but other times it requires me to put my foot on the break and release it by hand, what decides this - is it whether I'm on level ground?
Tramping. I've read a few people use this word - but I've no idea what it means, wheel spin?!
Wiggly back end. A couple of times I've put my foot down to over-take, lots of power- but as I accelerate the back end feels very light and tends to wiggle a bit. Is this where the sport and sound - rear stabilizer would have helped (I didn't go for it...)?