I now live in Thailand, but presently I am on a state side break.
I try to keep up with "things", even though there are some limitations of both my understanding and clarity of facts. I am not specifically well informed as to the specific areas that you mention. - Enough of the disclaimers.
The further south you travel in Thailand the more you see of a Muslim influence. If you cross the southern border of Thailand the more concentrated a Muslim presence you will notice. The Muslims of southern Thailand are trying to create a separatist movement to have an area of a Muslim state. Thailand finds this concept completely unacceptable. The Kingdom of Thailand, is the Kingdom of Thailand, period. Some of the Muslims have participated in activities that are terrorist in style and intent and done to create news headlines. In their way of thinking, creating sympathy for the Muslim movement. Last I read the opposite has taken place and there is no sympathy for the Muslims or their terrorist acts.
Thailand has taken a very authoritative position on this matter. They have increased the military presence and used any other authoritative agencies to maintain stability within the borders of the Kingdom of Thailand. They make very concerted efforts to stop or minimize ANY terrorist activity. At this point in time all separatist activities have been directed toward the government and not toward any tourist places.
Specifically within these parameters there is no need for a tourist to worry about traveling and finding themselves in the middle of a bloody experience. Even with that being said one should not completely put one's guard down. Muslim's in that part of Thailand have some disdain for westerners or the western style. For now that is not going to change. Since you are a traveler outside of your own neighborhood there is a very good rule to remember. Be alert to of your environment at all times. Speaking from fist hand experience - often you can sense trouble before the action of trouble takes place. One of my vocations was that of a bartender. This acuity helped resolve problems before they became real problems.
I don't say any of this as a deterrent. I simply makes these statement as advice to be alert as to where you are and if need be look for a plan B.
Putting this issue aside, enjoy your trip to the utmost.