I really need help with some details with vbulletin 3

I was hoping someone could help me here

I have recently installed vBulletin 3..and i have everything near set up..except 4 things..there proberly the simplest to do but i cant seem to find the options to do it so im praying someone can help me so i can get my board up and ready

How do you disable avatar uploading and attachements?..i dont want these options as it would hit bandwidth

How do you make your admin/mod have a different color on the online users list

How do you change the width and height of avatars

And the last and most importent..i only want regestered users to view my forums..

I hope someone can help me..cuz im kinda stuck on them four things

Thanks

Louda