some questions for newbie on Co2

just got my new Talon w/ 20 oz tank and was very excited to shoot it even though it was almost dark. out of the box, the power adjuster was about 1/2 way so I cranked up to full. The first shot let out a steady stream of Co2 for about 2-3 seconds. the second shot was ok, the 3rd shot was the same as the first. I turned down the power, and it didn’t happen again. Questions:
1. is this normal with the power adjuster on high?
2. how do you keep your cheeks from getting cold?
3. is it normal to see condensation on the barrel?
4. do they make a butt plate for Co2?
5. where can I order something to quiet this down?

thanks for all answers. I never owned any pcp’s or bulked Co2, strictly a springer guy, but I think that is about to change. I was quickly trying to sight in the scope tonight, and shot a very good 30 yd group without even trying.