misc Questions for a new BukkitUser

Hey Guys,
I want so setup and install my first BukkitServer. It still runs Canary, but I want to change to Bukkit (CraftBukkit)

My test-server is running on Bukkit, it still lacks the plugins and other settings.

I have to look through problems with the number of plugins.

Example: At the moment I got installed Permissions (not tested). And now I read something from the group manager.

Or:
Should I use CuboidPlugin or WorlEdit? WorldEdit can indeed also Cuboid functions, which is better?

Which of the two is easier, clearer and with more commands are available?

Also, I do not know how I can single standard commands (who, warp, time, to the so on) assigning the later groups.

I would be really grateful if someone could answer me these few questions

btw: sry, my english is not perfect (Germany)

greetz Sh4d0w