Your AS grades are amazing! I know if you put the hard work in you could get more than one A*.
I got ABBC at AS in Geo, Bio, Maths and Chemistry respectively (I know, bad right?), got my A2 results last week and got A*A*A in bio, geo and chem respectively. For essay based subjects e.g. geo and history make all your notes according to the specification and practice timed essays for me was key! Maths like chemistry takes a lot of practice and understanding. I am sure if you put the work in you could get A*A*A* especially with your fantastic AS results.
As for applying to universities, why not? but always make sure your insurance is lower than your firm offer. I mean you may have regret if on results day you get A*AA etc. are start thinking " I could have got into that uni", if on results day you don't get an A*, you'll have your insurance to fall back on hopefully!!
Good luck! x