Might cat have polyps in ear/throat?

Question
Hi, I'm at my wits end.  My domestic short-hair buff tabby is about 7 years old and healthy except for asthma which is controlled with Prednisolone once a day.  About three months ago he started to sound congested when he purred with a kind of bird chirp at the end of the purr.  I took him to the vet the day after sounds started.  She stated that he might have respiratory infection or the sounds might be from his asthma. She thought asthma bec no runny nose or sneeze so Result: she upped his normal medication to double the dose for a week and then taper back to normal.  No change. 2nd visit blood work huff and puff tests done and chest xrays = everything came back negative except for asthma seen in lungs. When I got his medical record there are a few readings on the high side but she never said anything besides negative. {I can share readings with you if needed} She gave him a shot of Clavamox at this visit which it sounded like it got rid of the bird chirp but no other change still congested. Waited the 2 weeks for antibiotic - called her to report not much change and she prescribed a take home antibiotic to see if it was a resistant type of infection. He got diarrhea from the take antibiotic home meds and I had to get the probiotic powder to combat the condition. No change.  She said I had to bring him back in to get another Clavamox shot since it appeared to effect the condition and so I did and we had a long conversation about what was going on but it was mostly me suggesting diagnosis I read on the internet since it appears she is out of ideas. She did look in his ears with the scope but didn't see anything. She is very young just out of school and I'm afraid she's afraid to admit she doesn't know what's wrong with my poor cat. Her next plan is wait two weeks and see if he clears up with Clavamox then try allergy meds for another 2 weeks. SO ANOTHER MONTH OF THIS I can't do this to him. I asked about maybe a mass in his throat and that's is when she said they can develop polyps. She states the only way to look for this is with sedation and throat exam.  I'm afraid of sedation without clear plan since he's asthmatic. He is now terrified to go to the vet since he had a bad experience when they took blood for the huff and puff bloodwork. His condition is only the sound, there's no sneezing, runny nose, cough or any thing of this nature. All activities are normal, eat drink, except for he makes noise when sleeping once in awhile now. No head tilt or pressing but for years he's had a neurological twitch of his head.  This is what I call it, I told vet and they said video tape it which was impossible. It's a involuntary fast twitch of his head area from side to side, not very far just the twitch motion. I thought it might be from the Pred but vets say no.  His abnormal sound is like a loud purr with congestion in the lung but they are clear. Like fluid in the throat, it's hard to describe but a congested sounding cat with none. I have felt throat and find nothing.  Looked in ear and can't see anything also tried to open mouth and look in back of throat but can't see very far. Seems to eat fine and I might have seen him swallow after a purr maybe from fluid??  not sure.  I asked the vet if we could see masses on an xray and she said no but when I got his xrays I can see his soft organs and such and I can see examples of masses in online xrays. My questions are

1. Should I ask for an xray first to confirm if we can see anything in throat/head area before agreeing to sedation?

2. Should I take him to a large teaching school in my area and get a second opinion from a vet with more experience?

3. Does this sound like ear/throat polyps or something else?

4. I have been told of something named an ear citeology {sp?}When the vet takes a q-tip and swabs ear for white blood cells.  Looks under microscope to check for cells.  Very inexpensive.  Should the vet have done this simple test for polyps instead of putting him under first?

5. Is the head twitch signs of maybe something wrong/growing in the brain?

6. I just don't think I can wait anymore time the antibiotic shot has done nothing to effect this condition so should I act right away if this may be a growth of some kind?

7. Am I forgetting to ask anything of the vet?

I have searched the internet for hours and can't find anything like his condition with a clear result so I have to ask another doctor to review what has happened so far.  I'm grateful for any advice in this matter. I just want my cat healthy without scaring/hurting him any more.  Thank you so much and sorry so much info but I know it's difficult diagnosing anything via this method so I gave you most of the results I thought were important. I'm worried to death about my faithful companion and desperately want to help him.

Answer
With as many issues as this cat is showing and poor response to medications, I would recommend having her looked at by a specialist.  I see from your question that you are from Massachusetts.  Tufts has a great veterinary school with many world renown experts.  YOur vet can get you a referral there.

Polyps are possible and you would not be able to see anything without either an endoscope or a CT scan.