Welcome to the world of Blood Bowl. As a fresh disciple of Nuffle, I wish you luck.
Your assumption is mostly correct. Amazons have a good starting skill, with dodge across the board. However, as an
AG 3 team without Sure Hands, you will learn just how slippery the ball can be. Also, your low armor will hurt you, especially with a few early turnovers. Learn to prioritize your actions correctly.
To answer your questions:
1) I've never coached an Amazon team myself, so don't expect an expert opinion. However, you don't have the speed to run a fast game of any sort, or the skill for a broad scoring base. Your Blitzers are very good, used both offensively and defensively, get a full lineup of those from the start. A short passing game combined with a willingness to risk your linewomen in tying up opposition seems like the best way to go (opposition linemen have a hard time hurting them anyway).
2) Generally it's good to have 3-4 linemen pick block early on, the ones who sit on the line of scrimmage. After that there's alot to choose from, I'd start mixing in other skills after the first few blockers. I'm pertial to Kick myself, it's always proved a valuable asset in slowing the opposition cage building.
http://thenaf.net/ has alot of useful tips on theri forums.