Audi TT acceleration

I bought an 05 TT 3.2 ltr automatic a
couple of months go from an Audi dealer in
SoCal. It has 25k miles and one owner. The
car sat a lot and I had to replace 3 dried
out engine mounts right away. The problem
I’m having now feelis like a delay when I’m
initially accelerating from a stop. The
engine revs and a split second later the
transmission engages and the car bolts
forward. It also does it in reverse. To
preventing it from bolting I have to
accelerate very slowly until I feel the
transmission engage and then I can
increase the acceleration. I’ve also noticed
that when i put the car in park and take my
foot off brake the car will roll more than
seems normal until the transmission
abruptly stops the roll. My mechanic
checked the transmission fluid and told me
that this particular transmission uses a
thicker fluid that takes longer to warm up. I
assume that’s correct and I notice it more
when I first drive the car in the morning.
However it doesn’t go away once the car is
warmed up. I don’t know how the car was
serviced during it's 13 year:/25k mile life so
I don’t know if any damage was done. I
appreciate any advice you can offer.