Are you using Dial-up, DSL, Cable, or some other type of connection? Do you have a router or hardware firewall in addition to your system's firewall? Do you have just 1 computer or do you have your own internal network of computers? Those are a few of starting questions as the answers for one case may not apply in another case.
I think to have "full access" would kind of require putting it at some risk as after all, wouldn't that imply someone else could take control of your computer? Just think about what do you mean by "full access" as for me this would imply a nearly useless firewall in a sense while most folks likely do have things configured so that some things aren't done remotely on their machine like say taking it over.
What are the best or correct settings? So that I have full access without putting my computer at risk with a virus.