1) We have user groups. Administrators, Registered Users, Moderators, etc. Could you explain what you mean, a bit more?
2) Use basic HTML. < br > without the spaces will give you a new line, < I > without the spaces will give you italics, but remember to close the tag with a </ I >. Replace the I with a B for bold, or a U for underlined, or an S for a strikethrough.