Sorry for the delay..
Yeah, i know that its dangerous to login as root, I wz just asking because of my curosity, I am not going to do it on live n/w...tnx for the suggestion
For the second question, i read somewhere that localhost setting should be changed in Domain Name for accessing the mail from other computers, but now i know its a way to set the reply address (pls correct me if i am wrong).
Also, i will follow what you suggested for changing the themes and will let u you know....: )
Tnx a millions for your help....