Some Problems With Rm2k3

Hi, I just started using the rpg Maker software and i got some problems.

1. When I import the battle chracter sets, then when i go to add them to my custom chracter it's just a blank and so the battlecharset I improted corectly doesn't work.

2. I imported some different chipsets. They work find but when I run the game i can walk over the trees and walk on to the roofs of the houses.

3. Some thing happened and the songs don't play. Even the songs that came with the Rm2k3 doesn't play, but the sfx plays.

4. I want to make my chracter turn into a monster in the middle of a battle, how do I go about doing that.