The islands will be too “small town” I think, but Phuket is nice because it will have everything you need but not so chaotic if you live a few KM from the city center
Assuming you aren’t running late. You look rather sus hanging around the arrival hall before immigration. I guess you could hang out in a toilet for 30 minutes.
You’d probably not have to worry and just be the last person off the plane and go through immigration normally.