Hey there! I'm a Sophomore at Harvard who's helping run HAIST. Congrats on your acceptance to Harvard! :) Some initial thoughts, which others might disagree with:

• Harvard being inflexible seems wrong. My impression is always that all "prerequisites" are merely suggestions; to get around them, simply shoot the professor a very quick email. Taking grad classes is pretty common; I was taking one this semester, and a (Harvard) friend of mine has taken a few grad MIT classes in his Freshman and Sophomore years (both my and my friend's classes were CS classes). My understanding is that MIT has more requirements, but I'm unsure of this. Note that at Harvard, if you don't pass out of your language requirement, you need to take two semesters of a language.
• MIT has somewhat better classes to prepare you to work on technical alignment, I think. On the other hand, MIT classes are more time-consuming.
• I expect Boston/Cambridge to become an alignment hub in the next couple years (and I intend to help make it one). Currently, there's HAIST, MAIA, CBAI (https://www.cbai.ai/), and various independent researchers around the area.
• I suspect that it's worthwhile for you to put some minimal effort to apply to MIT/Stanford/maybe Harvey Mudd. Seems possible and bad if you realize, in a few months, that one of these colleges is much better suited for you than Harvard. But also seems fine to not apply, since I expect Harvard to not be a worse option in general for technical alignment.

If you want to talk to Harvard/MIT/Stanford students working on technical alignment, I'm happy to connect you with some people!

And if you end up deciding on Harvard, I'd absolutely love to introduce you to people in HAIST & to give you advice on anything and everything Harvard-related. :)

We are quite similar! I was also accepted to Harvard REA – exactly one year ago – and was too lazy mentally drained by the application process to apply to MIT after that. I arrived intending to study physics, but I've since realized AI safety is a much more important and exciting problem to work on. Seems like you got there a bit sooner than I did! HAIST is a wonderful community, and also a great resource for finding upskilling and research opportunities. 

I've only been here for a semester, so take this with a grain of salt, but I don't think you should be too worried about taking classes that interest you. It seems like professors are generally pretty flexible if you reach out to them, and it's easy to fulfill general education requirements with hardly any effort (I just took a class on "Anime as Global Popular Culture" which required essentially no work).

Let me know if you have any questions! I also have some older friends who can give you more specific advice. I sincerely hope I get to meet you soon!

First, congratulations - what a relief to get in (and pleasant update on how other selective processes will go, including the rest of college admissions)!

I lead HAIST and MAIA's governance/strategy programming and co-founded CBAI, which is both a source of conflict of interest and insider knowledge, and my take is that you should almost certainly apply to MIT. MIT is a much denser pool of technical talent, but MAIA is currently smaller and less well-organized than HAIST. Just by being an enthusiastic participant, you could help make it a more robust group, and if you're at all inclined to help organize (which I think would be massively valuable), you could solve an important bottleneck in making MAIA an awesome source of excellent alignment researchers. (If this is the case, would love to chat.) You'd also be in the HAIST/MAIA social community either way, but I think you'd have more of a multiplier effect by engaging on the MAIA side.

As other commenters have noted, I think there are a few reasons to prefer MIT for your own alignment research trajectory, like a significantly stronger CS department (you can cross-register, but save yourself the commute!), a slightly nerdier and more truth-seeking culture, and better signaling value. (To varying degrees including negative values, these are probably also true for Caltech, Mudd, Olin, and Stanford, per John Wentworth's comment, but I'm more familiar with MIT.)

I also think it will just not take that long to do one more application, since you have another couple weeks to do it anyway. I would prioritize getting one last app to MIT over the line, and if you find you still have energy consider doing the same to Caltech, Stanford, maybe others, idk. Not the end of the world to end up at Harvard by any means, but I do think it would be good for both you and humanity if you wound up at MIT!

My advice:

• You're certainly not going to go wrong with Harvard. The value of college is much more in the people you will meet than anything else, and Harvard's quality of student body is as high as anywhere. 
• When I applied to college I judged schools based on the quality of their economics department because I was convinced I would become an academic economist. Turned out to be very wrong. I think the chances you end up working on alignment research are low — maybe 20% — so don't over-index on that. 
• Of course you can take advanced courses in whatever you want! Information is free these days. Don't let the school's curriculum dictate what you pursue. It's OK to optimize to some degree for easy classes so long as you are doing something valuable with the free time you are gaining. 

Hi! I'm a current MIT student. Here's how it works at MIT. Feel free to reply back for more information:

MIT is great in terms of classes. Getting out of prereqs is pretty easy. You just talk to the professor and get permission to take their class. I've done this in two classes so far (this is just my first semester here!) and they approved me without a problem. I also took many concurrent enrollment classes in high school at a local university and the process was much the same. My experience has been that professors are very willing to let ambitious students take their classes, even if they're uncertain about those students' abilities to succeed (though they may caution against it).  You'll probably see the same at whatever university you choose to attend.

On the other hand, fulfilling general institute requirements (the general education classes at MIT) is a pain here at MIT. MIT offers advanced standing exams (ASEs) to get out of some of these, but they're only the most introductory classes. There is only one computer science ASE, for example, and it's basically a test of "Have you seen Python before?" If you're goal isn't to graduate, this isn't really much of a problem. If you do hope to graduate, on the other hand, it's a hard to get out of classes for which you know the material.

In terms of Alignment clubs here at MIT: I haven't been, but I've heard there is an MIT/Harvard Alignment club. There's also a branch of EA out here, and I've attended one meeting. I do think it's much bigger on the west coast though.

Overall, MIT is a great place, especially for people wanting to go into math/CS. I think you'd enjoy MIT a lot, and I definitely recommend at least applying. MIT's application is really easy--I did it all in one day (the due date for Early Action)--and rather different from other colleges'. For example, MIT doesn't have any essays (there's just lots of short answers), and many of their prompts are optional. I think you would be a great fit for MIT, and I'd be excited to see you come!