just so you know, u don't have tastebuds on the roof of ur mouth, . but its a good thing to have an appointment set up, better to be safe then sorry.
They will either set up a scan, try some different treatments first, or biopsy. If they biopsy, they sometimes will give you an option, but othertimes, they will just tell you how they will do it. I would let them know right away about ur dental phobia and let them know that you have sedation dentistry done and that will probably help them, and they will more then likely sedate or knock you out to do a biopsy if they need to.
Biopsy results can be a week to 2 weeks or more. I just had my first post treatment biopsies done on november 9th, and i got preliminary results that day that were negative, but haven't received the final results/pathology yet, and it's been almost 2 weeks. They will always tell you your results of biopsy/scans what not, and they will send them to the referring doctor, one who set up scan or performed biopsy. If you want ur dentish or general doc to have them, you will have to request they receive results or bring them a copy yourself.

Hoping this all is negative for you, if not, you have a good bunch of people here that will help you through this!!