This doesnt affect me as I am Australian, but In Australia, as soon as we hop on a plane, Social Security get notified via passport ID, and we have 6 weeks to get back before several allowances are discontinued, we have to reapply for some. I thought UK would react in the same way, regardless of your banking arrangements.
So how are you going to convince the immigration officer at the border on the way back in, that even though you applied for your visa outside Thai, their computer records show you were actually in Thailand. Given the numbers getting turned away at the border, I wouldn't touch that
My wife and I, both in our 70's have Macquarie platinum credit card, it comes with travel insurance as long as you book and pay with the card. It provides very good cover, last year my wife tripped and fell in BKK. Covered all medical and upgraded travel back to Australia. And the annual cost of the card was less than a quote for travel insurance my son got
Immigration are checking for serial overstayers, from what you have stated on here they wont be worried about you, just in case you get questioned have a prepared Itinerary you can show them. I have been coming and going for 50 yrs occasionally I get asked. I use the Tripit app, and just show the my projected trip details. Good luck
They will only allow you to have the app on one phone at a time, we upgraded our phones and we had to go to the bank and get them to authorise the app on the new phone by entering the imie number of the phone
Apply for a qantas premier credit card, with $6000 limit (thats that smallest amount) It includes Travel insurance, also Macquarie Platinum. As long as you pay for your tickets on the card you have Insurance.