I got an offer from Trinity. It seems that you have most things sorted.
Your non-law extra-curricular activities will be irrelevant to your application.
Make sure you do that reading. Try to find one or two areas of law/legal issues that interest you (as long as they not to technical) and read into them as well as reading generally. If you want good reading material sources, just ask.
Make sure that at least 75% of your PS is related to law. The rest should be a brief paragraph. Make sure it demonstates a substantive interest in law.
As for interviews, there are several important things to note
i You're obviously highly qualified. Try to forget this fact. Behave as if you're starting from afresh. Don't think that you're somehow entitled to/likely to get a place.
ii Be as calm and relaxed as you possibly can
iii Do not be passive. Obviously you will have to answer a number of questions, but nothing stops you from raising issues of your own, putting forward ideas and asking questions.
iv Be prepared for some tough questions. Your interviewers will probably be very nice people (mine were), but they want to work out how intelligent you are, so they will take you outside of your comfort zone and examine in minute detail anything you say.
v Be prepared to defend your statements (I was challenged quite aggresively on things I said which I later found out were exactly right), but also be receptive to suggestions/different perespectives. Don't be afraid of contradicting yourself or admitting that you were wrong about something (I did and I got in). They want to know how you arrive at a conclusion not the conclusion itself.
vi Find out the format of your interview e.g. whether it involves preparatory study
vii Be intersting and interested. And try to be yourself.
Oh yeah, before the interview do something relaxing. Bring a magazine/an iPod. Don't feel you have to talk to other applicants - they are irrelevant to what you are there to do. And 3 days before the interview, stop preparing intensively for it. You'll induce a mental breakdown. Flick over some things, but just start calming down.