Problems with new server

Hello,

im in the middle of setting up my dream server, but im running into some problems:
1. I installed bukkit along with worldedit, worldguard, sine then the hunderbar completly refills, even is i only use lets say a single melon.
2. I installed permissionsbukkit and i woud like to define some more default permissions, other than building rights, can i do that?
3. Im looking for a protection plugin, that protects all blocks a player placed inside a set area, without having to use signs and stuff. Can i use worldguard for this purpose?
4. I want to install more plugins, but im unsure which would be the best for: economy, shops, selling land, community building projects, minecart railroad, ranged chat, website authentication, monster control, seats and item use.

Im also looking for help to administrate the server, you can join my Teamspeak server at: 85.25.108.191:4000

Thanks in advance, Peace.