Im 95% sure Swampy has an international to domestic gate (DMK absolutely does, I havent flown through BKK for 4 years) which doesnt mean getting stuck in the general customs queues.
It's an old rule, honest. There's no limit on tourist visas, there is a limit of 2 visa exempt entries per year at a land border, came in beginning of the year.
nope, 4x6, it's not a passport photo size and I might be wrong but I think it may require a blue background as well. Why - welcome to TiT, This is Thailand.
TM7 form, 4x6 photo, copies of passport page, entry stamp and departure card and 1900 baht in cash. If you dont want to do it yourself G4T upstairs at Prom can do it for an extra charge.
A small overstay absolutely doesn't affect future visas - at least in my own experience. 1 day and 6 day overstays (the last one due to immigration baa mak mak) and never been called up because of it. Had an SETV and ED since.