Hi hikerdeb, as you can see from my signature we've had similar surgeries around the same time. Now I can't answer how fast you will heal or how much flexibility you will regain, since everyone is different, but I can tell you a little about my experiences (so far).

After my neck dissection I couldn't pull my chin up even one millimeter and when I tried (I say tried because it was almost impossible) to turn my head to the right I felt my skin pulling tight from my chin to my collarbone all the way to my left ear. I got a list of exercises to do from my physical therapist and in the beginning I did them 2-3 times a day. Since the radiation started I’ve been doing them 5 times a day and about a week ago I finally noticed I don’t need to bend my knees anymore when I look up or turn my whole body when I want to look to the side. I also had some trouble swallowing because of the surgery but the strangling/tightening feeling went away when I started getting some flexibility back in my neck. So if you haven’t yet, get in contact with a physical therapist and starts doing the exercises regularly. And if you’re already doing them maybe you should talk to you physical therapist and check if you’re doing them right. Maybe there are other exercises she/he can recommend.

When it comes to your other questions the only thing I can do is to echo what Christine already advised you to do and say go get it checked again. I would rather have too many biopsies done in my lifetime than have one biopsy too little.