Just my personal opinion on some of your questions…
In April, it would be too late to apply to any BFA programs, as well as a majority, but not all, BA schools. January may not be too late at some places though.
Safety schools…put a lot of thought into these…pick at least two so that there are OPTIONS if none of the audition schools come through. Find schools that appeal NOW for the safeties. Don’t just tack on safeties. I’ve had a couple students not get into their audition schools who landed at Muhlenberg, but had a few non-audition options and truly liked Muhlenberg a lot (note that Muhlenberg is not a safety for ALL applicants…depends on your academic profile). So, it wasn’t like things turned out poorly.
I think a gap year can be a good thing! And if the student reapplies the next year, the list should not be the very same college list again. I have a nephew who applied to college in another field of the arts and did not get into any of his schools. He took a very fruitful gap year. During that year, I came on board to help him through his college selection and admissions process. We created a brand new college list and he went about everything differently. He got into all of his schools but one that time. I would not enroll in community college during the gap year because many schools might make your child apply as a transfer student and not as a freshman applicant and that would make the odds much worse for BFA degree programs. The gap year can be used for many things, including additional training, work, travel, internships, etc.
Make sure your college list is appropriate to your artistic talents, and academic profile and well balanced in terms of odds. An evaluation by a theater coach familiar with those who apply to MT programs is worthwhile to see if your child is in the artistic ballpark of the schools on their list (which still means difficult odds but at least they are in the realm of consideration at such schools) and make sure they are in the ballpark academically to the schools on their list. The right list for an applicant can be key.
If your child has two safety schools that they truly like, they won’t be shut out of going to college next year, just saying.
Think positively for now. Cross the bridge later if necessary.