My daughter is a rising senior and we are going through the process right now. While my daughter has level 5 skills (specialty passes thru to full and standing 2 to a full) she competes with her school rather than with an all star gym. In my opinion that has really hurt her in the recruiting department. We have just had to try to figure the whole thing out for ourselves. She is talking to some Acro (NCATA) coaches now that seem interested, but is also looking at some competitive cheer schools as well. In general she has just had to do research online, fill out interest forms for each individual program and is now working to put together video of her skills (once again without help from an all star gym, or her high school for that matter.) Of course flying out to visit all the programs she is interested in just isn't financially very feasible. I find the whole thing pretty frustrating. Our kids are nationally competitive athletes, yet they aren't treated as such. I look forward to the day when they will be recruited out of high school just like any other kind of athlete. But that will be too late for us.
As for your other questions, I don't know anything about Stunt, but Acro schools say they follow NCAA guidelines. The students can't register with the NCAA though because Acro hasn't been accepted as a sport yet. My daughter initially turned up her nose at Acro due to the fact that it was all girl and not as flashy, but after a couple of days at an U of Oregon camp she is coming around. I like it because they give significant scholarships, treat and accept the girls as the athletes they are, and are super safety conscience.
Another bit of advice is that every school and different kind of program is looking for different types of video. Programs that cheer games want to make sure you include footage of that and care about your "look" and personality, and Acro programs want to see tumbling on a non-spring floor (not that easy to come by for specialty passes.)
My daughter has just a few months left to decide on a final list of where to apply, and then she will have a final decision by next May. If you are interested in an update after we finish the process, message me and I will let you know.