I will be there next month for some months
Offcourse you must see pattaya (when you are alone or with friends)! That is like Disney world for horney people. But than relax on the nice islands Thailand has to offer. I will travel around a little but mostly stay in a nice place at a beach somewhere. i just land at Bangkok and than decide where to go next).
You never know if things get stolen, they broke into two Bungalows next to me at Koh Chang. But after that happened the manager put on extra fences and cameras. Just have a travel Insurance and back up your pictures.
Drugs is strange nowadays in Thailand. I have been to places where everybody was smoking marihuana, they bribed the right people. While i know that friends of mine where caught at a full moon party smoking a joint got arrested and had to pay his way out. Also i know someone who had 1 XTC tables and he got 6 years prison.... So best is to stay away from it!
Don't worry about the ladyboys, blame it on the beer when you wake up and don't tell your friends.