I’m glad I found this post!!! I’m not in your exact situation, but I did have the option you have now: either graduate early or attend community college while still in high school.
when I was in HS I didn’t feel challenged and my parents did not have the money so private school/boarding school was out of the question, so I went to my guidance counselor in 10th grade and asked her how I could graduate early – she said because the school gets funding for every child in the school, I can try to graduate early but they’ll probably make it hard for me. A few students had done it before, but its 'cause theyw ere in ROTC or other special programs. the other smart students in the school, instead choose to take dual enrollment (classes taken at a community college while earning high school credit) – after a few sessions she finally convinced me to go the dual enrollment route. to make a long story short, I graduated with my AA degree so I transferred from my HS to a state university as Junior. But I lost one thing: my first choice major – I wanted to major in chemistry, but I’d only had 1 year of HS chemistry so I couldn’t hack Gen Chem I with Qual analysis. So I had to W/D from that class. Instead I majored in English education. So I went to a state univ and graduated HS with my AA BUT I feel like I missed out on a quality education, which I could have gotten at an Ivey – I never took AP classes, and I’m in field I like, but don’t LOVE. So, here are my concerns for you as I’m experiencing them myself:
<li>If you go the comty college route, you might not get the education you want. I found myself turning in mediocre work, and getting As and Bs, online quizzes, books they told you to read, which I never did, but passed the tests with flying colors anyway Comty college students are not necessarily the ivy-seekers, they’re nontradiational students, who waited to go to college, some not very motivated, some weak in language or math and taking prep courses – and comty colleges have to accomodate those students. So, as I’ve noticed, their standards are lower – because their student body is different – whereas princeton, yale, harvard, upenn, cornell, and the other ivys cater to students who took a rigoruous curriculum in HS, have a work ethic, and are the brightest of the bunch. they have differnt standards. so, again, you may get some college credits, or your AA but you may not get the education you want. </li>
<li>in terms of taking the AP tests…from what I’ve read, I’d def prepare for them, take them, and see what scores you get – if you can put them on your college application it’s only going to make you look better, right? (and anyone on the board can correct me if I’m wrong). I’m thinking about taking some of the AP tests myself to see if I can do well on them!!! lol, but being a college graduate I’m not sure if I’m even eligible. But I’m into the challenge 
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for transfer rates, I’d go with what hoopser said and email/call them, he’s right…I don’t know how many ppl would have the info, admissions would prob be the best to ask 