WordPress MU

hi,
how can i set the new blog user role is editor not a administrator ?
and set the editor have persentation permission to choose theme,i dont want to the new blog user can choose the plugin.

i know have a plugin "rolemanager", it can change the permission of the role , but it need to change the role permission manually by site-admin on the new blog.

where can i set the editor role permission to be a default setting?

thank you

For that you'd have to hack the code. Why not just turn off plugins?
Go to Site Admin -> Options and scroll to the bottom of the page. uncheck the box and users won't be able to see the plugins menu.