S. J,
Your heart seems to be in changing so I'm not sure why you are reticent to do so. In your current pediatrician's defense, I'm sure her missing the diagnosis was not intentional. They see the "same things" often times in those rooms and "go for" the simplest diagnosis initially; if, in follow up things aren't tracking well, they tend to move on to the next thing. In fact, congestion in infants is normal. All that being said...
I have always been a patient who INSISTS on a relationship with my doctors. If I feel rushed or dismissed, I move on. I do, however, make it clear with any medical provider this is the case. I want to work in concert with my medical providers, not turn my care over to them, and have been really fortunate in the healers I have worked with. Our family pediatrician is always slammed and would rush me out if she thought she could (smile) but our appointments end up being REAL appointments.
If you have to move to the family practitioner, as long as she/he is a good one, I don't think there should be a problem. You must take the time to interview whomever you are considering. It's an absolute must, particularly now that your child has a diagnosis of RSV. Find out what the doctor knows, understands of the illness and get assurance from that doctor that they are on top of RSV and it's assortment of treatments. Also, owning up to your discomfort with the move will encourage the physician to find ways to assure you your family care is a priority. Don't be intimidated by them or allow them to rush you out or dismiss your concerns. Be a pain if you must but remember, in fact, that if you aren't on top of your health care and the care of your family, no one is.
I grew up with a family practitioner as did my siblings and we're all fine (smile). AND if today I were having children I would have them with the GP I see because this doctor is amazing (and expensive as he doesn't take insurance because he found the insurance companies were making him less of a doctor, not allowing him to spend time with his patients, making him feel like a worker on an assembly line - which was not the reason he opted for a practice). He has become a huge part of my family and my life - just as the physician from my childhood was until I moved away from the area.
You can do this, Kiddo. Good luck.
Peace.
J.