Babiespalace - I know how frustrating dealing with doctors on your child's behalf can be. My DS was a micro preemie, so needless to say, even 7 years later, I'm still dealing with different specialists and therapists daily. What you need to keep in mind is YOU are the customer. Some docs (and it sounds like this ENT is a prime example) have developed God complexes that make them think that they are doing you a favor by seeing you. When I go to a doctor like that for myself, I don't go back a second time. The problem is for child specialists you are limited.
Anyway, I think tubes are a good thing for many reasons, and if your DD is having drainage problems this will definitely help keep her from getting ear infections on top of everything else. Also, I agree 100% with BYHOPE - get her to a pediatric pulmonologist now. Don't wait to find out if the ENT is right - that just takes too much time and she needs relief NOW.
Do you nebulize her with the xopenex before bedtime? I'm also not a medical expert in any way, but my BF's 2 son's both have asthma and when they are having problems she was told to nebulize before bed to open their lungs up.
Did the ENT say anything about a decongestant? You might want to try some OTC children's antihistamines and decongestants to help dry her out a bit.
One last idea - Is there anyway to prop up the head of her bed at night? I think this would help as well. When I had really bad problems earlier this year, I found propping myself up helped me breath, and therefore sleep, better.