i can go there at 10pm, no problem, as long you can get my re-entry permit. it's easier than spending 2 hours to go samut prakarn immigration which is like 30km away
he can apply for the non-o and should get it, hower when they are here, they need to register the marriage in thailand. immigration will come once a year and check on him, untill they have a baby.
lastname on ID card is unimportant, since thais can change it as much as they want.