, no guarantee. The max. penalty is 10,000 THB but is meant for hotels and the like. Go to Immigration with your (Thai) house lord and tell them that none of you knew about this until recently 🙂
Your immigration should be very hostile if doing the TM30 reporting late and getting a ticket for that (max 2,000 THB for a private property owner). I didn't get a ticket even though I originally did it more than one year too late 🙂 when going from multiple Non-O into Non-O extensions...
I have not tried this specific trip. But as long as you are not returning to Thailand on the same day, it is hard to see why this should cause any problems. Some border stations have the idea that "90 consecutive days" means that you cannot return to Thailand on a multiple Non-Immigrant visa the very same day as you are leaving Thailand.
You have to show up in person. The basic requirement for a foreigner to open a bank account in Thailand is to have special relations with Thailand. This could be being married to a Thai national, working in Thailand (having a work permit), or "just" having a "permanent" stay in Thailand. "Permanent" stay will be proven by having a Residence Certificate from Immigration. At some/many Immigrations this is very easy to get even being a tourist staying at a hotel. The well-known exception from being easy is Bangkok Immigration. You can also pay an agent to help you but rarely necessary.
, if you qualify, you can get Thai lifetime residency. If I remember, it only costs you around 100k THB... But other requirements including language skills make it very difficult to get.
, are you absolutely sure that you will be able to get each entry extended by 30 days? There are reports in other visa groups that at least some Immigrations will only extend your METV once (by tourist extension)...
They might very well be more careful about the requirements for accommodation, return tickets, and the mandatory 20k THB in cash. I would be sure to get your daughter to come to get you at the airport and call her up and let Immigration officer talk to her if needed.
It is not without complications to drive your own car into Laos bc. they drive on the right side while Thailand drives on the left side of the road. Most ppl. would drive to the border, walk thru the border station and pick up a taxi on the Laos side. The easiest route from Chiang Mai might be to fly to Vientiane or fly to Udon Thani and take a bus to Vientiane from there.