Can you take with you a Thai person of 'standing'? Government workers, especially schoolteachers can be useful. My visa agent told me that Thai banks are nervous of money laundering but Bangkok Bank don't care so much.
Problem is US banks are very nervous of VOIP services and almost all won’t send OTP’s via SMS. Thai banks (certainly Bangkok Bank) will only accept Thai mobile numbers. It’s often good to carry two phones in case of flat batteries. For $16 USD per ANNUM you could rent a US mobile number from ‘VYKE’. Calls and SMS are free to receive. The caller/sender pays for a US mobile call/SMS and thinks you are Stateside. Outgoing calls and SMS very low cost. You would, of course, have to advise your contacts of your new VYKE number. Alternatively, VYKE customer support can port your existing US mobile number. Unfortunately, VYKE is a VoIP service so you couldn’t receive OTP’s. The only guaranteed way to receive OTP’s would be an actual US SIM card. If you could find a pre-paid SIM and turn off the mobile data you would be able to receive OTP’s in Thailand free of charge. Any calls received you would have to not answer.
Entry is always at the discretion of the individual immigration officer on the day. Even possessing a tourist visa doesn’t guarantee entry, neither does being able to enter visa exempt.
I was advised to only take out a policy issued from your home country. A claim may be refused if the insurer can establish that you had a pre-existing condition, whether diagnosed or not.
If your homeward flight departs around 1am you would hopefully pass through immigration (manned or automated) prior to midnight the day before. No worries.
If your phone only has one SIM card slot and/or pre-dates eSIM’s (as does my iPhone 8 Plus) you could choose to buy a pocket WiFi router. Otherwise, if you don’t need continuous access to mobile data, free WiFi is widely available in Thailand in hotels, coffee shops and even the most economical noodle restaurants.
Strange. My Mrs recently attempted to send a PROHIBITED item from our local post office. I ‘advised’ her it was listed as such on Thai Post Office website. Unconvinced (she thinks I know nothing) she took it herself to the Post Office. They said they couldn’t accept it. However, no police involvement. A friend has an outstanding UK arrest warrant. I knew that it was safe to fly into UK because Border Force have no access to (and even less interest in) UK Police National Computer. One of the ‘experts’ on here insisted that they have all sorts of apps and check for warrants. My friend has since flown in/out of Manchester Ringway Airport three times since and remains at liberty!