If the new passport is an e-passport, which it probably is, you use that to depart using the e-gates. Basically you just carry the old passport for reference but in practice only the new passport will be stamped on entry and used for exit.
Relax, you won't be asked for "proof of accommodation". Just fill in the TDAC before arrival and present your passport + DTV printout and you'll be fine. I've been in and out 8 times with ZERO questions asked.
That's nonsense. She can keep the DTV until it expires. Once the DTV is issued, nobody is checking for it's "legal basis"! As long as she leaves every 180 days or earlier she'll be fine. Only visa agents want you to worry about "legal status" because worrying about your visa all the time benefits them.
Forget Chat GPT, it's lying. Chat GPT will also tell you that some nationalities (including mine) are not eligible for the DTV, which obviously a lie because I got it without issue.
That's against the DTV rules. You can't legally earn money from a Thai business while on the DTV. What's so hard to understand about that? Switch to a work permit and get the correct visa.
You really have something against Africans, huh? I'm Nigerian, applied at home, and got my DTV in 10 days. Having a Nigerian passport is not a "red flag", and besides, many Nigerians are getting the DTV, and NO, it's not taking us "8 - 10 weeks". That's total NONSENSE! That time frame may only be true if we're not in our home countries, like an African in Malaysia, instead of his home country Nigeria. Then it may take longer. Stop spreading misinformation about African applicants. I'm sorry to disappoint you, but from my experience, Thailand treats us fairly!