hi there and welcome to this forum
you'll find a lot of good info here
http://www.thamnophis.com/caresheets...ake_Care_Sheet
as to your questions
1) I've only got struck a couple of times or so - when I had food smell on my hand
2) depends on the snake (size) and the type of food
my grown garters (ca 26") eat a fuzzy once per week
the babies eat a quarter pinkie every three days
if you are feeding fish, please also read this
http://www.thamnophis.com/caresheets...?title=Thiamin,
3) the aspen stuff is fine
there's a whole thread on bedding
The Best Substrate
be aware that he may not eat for a few days
just give him time to settle in
please ask as much as you need to
nice to meet you