Need help with essentials plugin and some others, ty!

Hello! first ty for considering helping me!

im new to the whole hosting your own server thing, i was using MCAdmin, and since its been discontinued ive switched to bukkit, I was hosting a server just for me and my friends but now I kinda want to make it public but to do that I'm trying to secure a few things.

ive got groupmanager, essentials, essentialsprotect in my plugins.

the only thing im having trouble with is the essentials protect, ive went in and blacklisted the items i wanted in the config file, and its working, like i can lay tnt and it goes off but instead of doing damage the area goes back to what it looked like, but when i try to add
essentials.protect.exemptplacement
essentials.protect.exemptusage

into certain groups in the group manager, it wont allow those people in said groups use the items ive blacklisted....

if you could explain what maybe im doing wrong id really appreciate it, or maybe hop on vent and help me out :-/. ty!