In Thailand cross one's legs when have conversation with people who less than you or same age. It isn't bad manner. Receive things don't use only right hand but you should say thank you every time you receive. Touch other, if don't know each other we don't touch them. In Thailand you can holding hand different gender if you love each other and holding hand to greet isn't bad manner.
Social manner of Brunei people and Thai people are different because Thai people isn't do complicated like Brunei with Islam people for example when receive something from others, they alway use right hand but Thai people can use both but must say thank you every time.