My 2 cents
Background, for what it's worth. I taught college, have been on scholarship committees, although not involved in admissions and I'm not in academia anymore...
If Rite has a couple schools in mind, take a look at anything you can find on their web sites about admissions. That may help you decide on AP vs PSEO.
For admissions to a place like Stanford, you should ask someone about transfer credits from the PSEO. If Rite goes to school in state those PSEO credits should transfer directly to in state colleges because they are simply credits for classes taken at a real college. Given that the state sponsers the program, they should have some sort of transfer policy to make sure students get credit for these courses when they enter college after graduation. Besides, many colleges have transfer agreements with colleges that their students are likely to transfer to or from. For example, most community colleges have articulation agreements with nearby 4 year schools. This sounds like a great option for a student who stays in state because of the potential to have so much coursework paid for by the state.
HOWEVER transfering college credits from one college to another can be extremely tricky, especially for distant schools. Many times courses are examined individually for acceptance. There are no guarantees that a course taken at one institution counts for anything at another. Generally, a completed degree is somewhat easy to transfer, individual courses are more work. For example, a general ed associates degree at a community college should allow you to tranfer to a 4 year school with jr status. You are typically able to start in upper division degree coursework, although you may need to take a few lower division courses specific to your area of study. Most importantly, the general education courses are usually considered complete.
On the other hand, if you have 15 classes to transfer, the college will look at each class and decide whether or not it counts under their system. This tends to create holes in lower division general ed -GE- coursework because diffent schools have completely different ideas about what is needed for GE. If Rite is planning to go out of state, the college coursework may not be as easy to get credit for as the AP tests.
