I agree with @MrylndMom. If you are applying to a school that guarantees two things (1. Need blind admissions, 2. Meets full need of admitted applicants), there is absolutely no reason not to apply ED for financial reasons. True need will be met. (Yes, it might affect non-financial need, merit-based aid some places, if you don’t NEED fianancial aid but would appreciate some merit money if you could get it. In that case, wait for the RD round.)
If the school is not need blind or does not guarantee to meet demonstrated need, then it also would not be a good idea to apply ED if you need money. But schools like ED Ivies will take care of meeting your need either way and you will not be taken advantage of just because you committed early.
I also disagree that you need an overwhelming first choice to apply ED. In fact, I think almost the opposite: putting all your emotional eggs in one basket is a recipe for terrible disappointment if you do not get in. If there are a few colleges at which you think you would be happy as a student, it makes strategic sense to pick one of them to which to apply ED. Just look up “early decision acceptance rates” and compare them to regular admission rates! If you are someone who rues decisions and thinks you would always wonder “what if,” avoid ED. If you have a college you really like that you are not likely to get into but want to throw an application their way just in case, avoid ED. But if you think there are a range of colleges at which you would have a great education and a happy experience, and you have stats in line with most students at these colleges, there is no harm in picking one for ED. If it works out, celebrate and do not look back. If it does not work out, you can apply to the other ones you like and be happy when you are admitted to one of those RD.
You definitely should do your research and visit, to be sure that are no indications that the college might not be a good match for your needs, interests, and personality, before you apply ED to a college.
Early Action vs. Early Decision… There is no reason, other than a SCEA or REA agreement or a desire to raise your grades or scores in the fall of senior year, not to apply Early Action to any schools you like that have it.