Pace of Life
Although typical farang behavior might suggest otherwise, Thailand is a very conservative country. Family values, chaste conduct for girls and the institution of marriage are important even for the more rock'n'rolly types. When speaking with Thais about those topics, it shines through that they are not very happy with how many tourists behave in their country, and complying with some of the basic rules will earn you not only respect, but also lower prices and friendlier faces. Running about without a shirt is considered pretty tasteless by most Thais, who will even go for a swim fully clothed. Same goes for showing (opposite sex) affection in public, so smooching (not to speak of shagging) when other people can see you can anger some Thais, even if they might seem unperturbed. Employees in tourist resorts are obviously more understanding of the cultural differences, but from what I gather they still consider you to be a pretty lose person, especially if you are a woman. Hollywood hasn't helped that issue, giving many Thais the impression that all western girls are pretty much all hookers and nutcases.
Thai girls who get physically friendly in public, especially with farang, are looked down upon, even if they are not prostitutes, and for many Thai men intact virginity is still an important asset when choosing a partner. Just like in Iran, men are expected to enter marriage with some sexual experience despite universal chastity of girls, so the inevitable result is flourishing, if illegal, prostitution (see below).
It's considered polite to watch people's glass contents and pour new whiskey and ice if it's nearing empty, which means that you should drink steadily and slowly, as helpful friends will refill your glass every time you run out. While this can work as a subtle way to control your friends' intoxication level, be aware that, since you are farang, you are considered to always needing way more then your new-found friends, who'll do their best to get you as drunk as possible.
By far the most common drink is beer and whiskey (also for girls), but all my Thai friends heavily discouraged me from drinking the cheap issue Samsong that is found in most cocktail buckets. I mean, if someone offered you a bottle of Whiskey for 2 Pounds in Europe, would you drink it? Exactly.
Even without any scandals, interest and belief in Buddhist doctrines is on the decline. Fewer and fewer Thai boys undergo the traditional period of being a novice and many smaller monasteries have funding problems. If you join one of the monk chats offered in bigger cities, you'll find that the majority of young monks is more interested in haircuts, punk music and the girl next door than their spiritual advancement.
Much more frequent then most foreigners assume, gatoey work in many different levels of society, and many of them eschew the drag queen style so often associated with transsexuals. As an example of the fluid gender identities in Thailand might serve Nong Tum, gatoey actor, model and Thai boxing champion. Working in my acommodation at the reception, a gatoey named May explained elaborately to me how much she hated ladyboy prostitutes, who would give all people the impressions that gatoey are hookers. While we're at that topic, a word of caution: ladyboy prostitutes are often heavily drugged and prone to violence, and incidents of stabbing are common. Besides that, ladyboys are quite well accepted in Thai culture and even have their own language particles ('ha' instead of krap/kha). Tolerance is not as prevalent (unsurprisingly) in Christian and Muslim communities, where they are presecuted or outcast.