Here are my thoughts/insights, for what they are worth:
1) The meds/treatments all sound perfectly like he is being treated at an appropriately aggresive center, meaning giving the "standard of care" for maintenance. The pulmocart I am not familiar with but googled and it looks like it is for asthma, so I guess if you aren't aware, I'd ask if there is an asthma component. Re the treatments and vest: Important that they are done daily, no matter how he feels, etc. The compressor for the nebulizer and the vest machine both have filters which need changing every 3 - 6 months. You might consider asking for new filters to change now since you probably have no idea when they were changed last. The nebulizer cups need to be washed after every use and sterilized every other use. Have they gone over that with you? If not, I'd call the nurse and ask for info and/or check the "instructions" that came with it. Make sure you are using "durable" nebulizer cups and not "disposable ones" the later of which cannot be steralized. Pari LC Plus is a very typical one that is durable. We order/pay for extras so we can sterilize and have ready several at a time.
2) The typical CF schedule is quarterly CF appointments and certain things done annually. I'd ask at the quarterly where he is at for annual tests and whether they should be run now. annually they do blood draws to make sure there are no vitamin deficienices. And also lung xrays to check for structure changes. I'd also ask when they start testing for CF related diabetes (CFRD). I think it is 12- 13, but just so you know when that testing starts. They also might do more intensive lung function on an annual basis--our son is too young for that so not sure. Re the typical quarterly appointment. A tech will take vitals and do height and weight. They want a BMI of 50%, but don't start pushing food or it could backfire! A tech or nurse will review all the medicines and see if you need refills. A social worker and/or psychologist will likely come in check on you. The nurse will do a throat culture to see what bacteria he is growing. Some are fairly harmless (staph, hemophilo-influenze? sp??),others can be pretty serious. The "harmless" ones they usually don't treat until he gets sick/has an excerbation. Others like pseudomonas they try to erradicate. You'll get the results in 3 - 5 days after the throat culture. You'll see a dietitian as well who will likely discuss meals/food, vitamins and enzyme. The doctor will then come in for an exam. If he has GI issues, he may also see a GI specialist. (But given that he doesn't take Miralax, Zantac, or Prilosac, he might not have any. Which leads me to remember to let you know that "constipation" for CFers can be a series condition and not constipation, so I'd find out if he has any history of issues and also just that you are in the loop with his "stools." They ask about "stools" at the CF appointment so that might be a time to ask your foster child how he wants to keep you updated on those or ask the nurse how children typical do it at the age of 9. They do lung function I believe at the quarterly but our son is too young so I can't help with that.
3) I would think there would be some issues that are "normal" for foster kids to face, which take on an added dimension with CF. I LOVE the book parenting chilren with chronic health conditions by Lisa Greene. I'd strongly recommend you get a copy of that, but also to schedule a separate appointment with the psychologist if there are concerns, etc.
4) Finally, when he gets sick, any time you are unsure, call the CF clinic. That is what they are for and they can help you assess what is going on.
5) Oh, I guess the final final is that CF is caused by having 2 CF mutations and there are more than 1000. I'd find out what mutations he has. The most common is d508f. If he has two copies of that, that is good to just know in the back of your head. IF he has another other mutation, then please post it and ask for insight because there is a drug called Kalydeco which can help "fix" (truly a miracle drug for some) those other mutations. Hugs and prayers momma!