I think this is a nice place as compare to Myspace and facebook, which I still try to find out what can we do over there. The only problem for this site is that we do not have a free e-mail account. But overall I like it, and my English is improving as well
Your hosting account is set up in rather an odd way in order to enable you to run several sites under the same account.
If you mean the root of the whole account then no.
If you mean the root of an individual site then, as you have free hosting, it depends on the file type.