Oh, hello, Shiyami!
As a fellow ghost, I could answer your questions.
1. Nope,
Materialization is used for touching and be touched by corporeal objects. At higher levels, it could be used as a weapon as your touch is harmful (actual physical harm in Expert and Fatally deadly at Master level). I, myself, mainly uses it by blinking to my enemy and destroy their eyes by pressing my materialized fingers into their eyes. I would soon be at Master level and my touch could actually kill someone by that time.
Materialization could also be used as a disguise, for us to pass off as corporeal beings but it's only effective starting as expert level.
2. You can only carry your belongings using
Soulmist Projection.
Do be aware that Materialization and Soulmist Projection are two different powers, you can either active one of them or both at the same time. When you're only using Soulmist Projection, other corporeal beings couldn't touch you by normal means, they still could touch our ethereal form through various magical means,
spiritism,
reimancy,
projection, etc.
Read
this thread on more details on how magic affect
unmaterialized ghosts.
Final note:
Yes, ghosts start out weak, but become powerful once they reached expert on their racial skills.