Hi there,
From what I know, search engines regard
http:// and
http://www. versions of your site as totally separate and different pages, despite only actually displaying one in the search engines for a given search term if they contain the same content. This is not really a major issue unless people start linking to your site using only the
http:// extension rather than
http://www. as the credibility these links give you is separated as well, rather than consolidated to one URL.
I would certainly recommend implementing this redirect on your sites as best practice and to eliminate any future risks.
Implementing a non www. to a www. should be simple using your .htaccess as you suggested. Would you mind posting the URL that your having trouble doing this with? I may be able to help with a closer look.
In regards to the
https:// issue, perhaps this thread will help:
http://www.google.com/support/forum/...e4698c88&hl=en
Let me know if not and I may be able to dig something up.
As far as Hostgator go, I would never recommend them

cancelled my account with them around 6 months ago and they are still invoicing me for a dedicated server every month despite numerous phone calls!
Cheers,
Dave