Given the information, Cambridge may unlikely - the average successful applicant has between 94-96% UMS average over their top three most relevant subjects, so you are seriously going to be up against some competition. From reading posts by the Corpus admissions tutor who is floating around somewhere on this site, with less that 85% UMS average you may struggle to get an interview. However, you do come from a particularly bad school and so they may take this into consideration. I would say that don't get your hopes up but since if you don't apply you haven't got any chance, you may as well apply - you still have 4 more spaces left for safer choices.
I don't know about the exact entrance requirements for your universities, but most of them are likely to be reasonably high. I would advise applying to 1/ 2 'aspirational' choices - a grade or two about your likely grades (rather than predicted - so for you AAB are your likely grades assuming you didn't get 90%+ in any of your ASs so A*AA is fine for an aspirational choice course - probably Cambridge/ Bath/ Nottingham?). Then pick 2/3 at your likely grades (AAB/ AAA - probably Birmingham/ Surrey/ Nottingham?). Finally, pick a 'safe' choice below your likely grades - probably ABB/ BBB. However, make sure you would feel happy studying at any of the universities you apply for, don't just base it on grades - some universities may be surprisingly lenient on their entrance grades, whereas others may be much tougher.
I would say that you should have a good chance at receiving offers from most of the universities on your list, so an application to Cambridge would be worth considering. Your only difficulty may be achieving your offer grades - as I said, try to have a safer insurance choice just in case your exams don't go as well as you had hoped. A2 is much harder than AS so there is no guarantee you'll be able to move up a grade in one/two subjects, or even keep the same grades.
You're coming up fairly close to the Cambridge application deadline, so make sure you have perfected your personal statement and completed most of your UCAS form pretty soon - remember that your school needs to attach your reference and predicted grades in this time too and so submit your application preferably a week or more before the deadline to give them plenty of time to do this - they may have their own internal deadlines too (e.g. my college required us to complete our form three weeks before the official deadline).
EDIT: I also just realised that you didn't do Physics A level, which may be a small problem for some universities - double check their entrance requirements to confirm that it isn't required