went to a new amp and foolishly answered no to mamasan when she asked me if i had been there before.  then she asked to see my DL.  I said I wouldn't hand it over but would let her look at it.....she took a good long stare at it in my hand and then said my birth year out loud.  really freaked me out a bit.  I was out of state at the time.  Do you think I have anything to worry about ?

Each time I see someone for the first time, I show my drivers license. Haven't had a problem so far.

I also ask to see a DL when meeting new clients for the first time and I am normally asked to show one when I go for massage.  SOP

I've never been asked to show my DL at an AMP, but I wouldn't worry about it too much if I was asked.  I highly doubt the person scrutinizing it has a photographic memory and could recall any of the info if asked (except maybe my first name).  For your situation, since she said your birth year aloud, I'm guessing you look young and she wanted to make sure you were of legal age.  You shouldn't be concerned at all.

I've had to do this a bunch of times. I'm in my thirties but have been asked a couple times for it. Twice I had to go out to my car and get it cause I didn't bring my wallet in (usually I just try and bring the $$ in with me)  
I wouldn't worry about it. They are just are just trying to cover their asses.

Make a copy?
write down your name and address?
ask for your insurance info?
take your phone number also?
call your wife to verify you?
if you answer no to each of these questions, stop worrying.