Can I add other admins other than myself in the CP? What are the ramifications of this, do they then have all the CP powers that I do?

Yes, you can promote any number of users you like to admin.

If you do, they have all the permissions you have with the exception that you can remove their admin status, but they cannot remove yours. This leaves them a LOT of power within the system to do nasty things if they so chose.

Give out this power very sparingly and only to someone you fully trust.

There is not a lot of granularity for assigning permissions to the CP functions.

What is it you want to do?

To add on to what Mike stated, you can also assign groups (such as the moderator or global moderator) access to edit users without having to make them admins.

I have a global moderator who I wanted to make look like the admin, so I changed his display name colour to red and even gave him a personalised "Administrator" title.

Now everything looks great apart from one thing... when users go to the "User List" section they can still see him listed as a "Global Moderator". If that list would show him as an "Administrator" (without having to assign this status in the CP) then my problem would be solved.

We did something similar years ago in version 6, forget the code though. Basically we put in the script in who's on line where it checks, if user id="123" display Admin

just change the wordlet for 'Global Moderator' to 'Admin person'

2c