I can't answer the last question, but see reply in the Siam Uni thread for some general comments about "leading" Thai unis.
Re. Thammasat:
Ages ago, I did not attend a Thammasat interview because over 60% of the classes were at Rangsit (way out of town) and then I was expected (next morning) to commute to the river campus too. The Rangsit commute could be (total) 2 or 3 hrs daily, in bad traffic. Maybe OK if u live up there.
Re: 1000b an hour!
I understand that Chula pays even more for "overtime" private courses (usually in other faculties). A friend who left there recently told me it used to be 2500b AN HOUR !!!but the management resented the fact that farangs were managing and delivering these courses very well 'outside' of the language faculty.... and sliced off 10% of the farang wages for 'admin costs'. The Thais promptly screwed up the 'admin' of the courses, and in the end it got so bad that the farangs took back managing the courses for free, despite losing money. To add insult to injury, the Thais promised that the 10% would pay for new teachers to relieve pressure on the farangs (cash enough for 4 but only 1 was appointed...good profit).
Re:Salary
The previous poster was right. The gvment uni salary is 26,000b. This is 18,000 basic (YES!!) but 8,000 housing allowance added. U can't live on this money, so u have to do the overtime. I couldn't live on this, so I left a public uni 2 yrs ago...but I left also because of the sheer ineptitude and incompetence of the Thai 'management', and the way that farangs were exploited while Thais gossiped, ate noodles all day and took huge sabbaticals/jollies while screwing up everything they tried to do.
If you can live on the money, your hours are about 12-15 teaching (but u have meetings and paperwork). Your visa and WP should be sorted effortlessly, in any case.
M