Yes, I did take that into consideration. She will be going back to Thailand at the end of September. Hurricanes are not unusual here at that time, and that would really throw a wrinkle in "down to the wire" flight plans. So she is going back a week before the 6 months limit is up.
Talked with an immigration attorney this past week. Interesting conversation. He mentioned that not knowing my plans concerning marriage, if any, he advised me to definitely not plan on marrying within 30 days of her coming to America, and be very retrospect of it between 31 days and 90 days. That is when using the B1/B2 VISA. Apparently within 30 days marriage triggers a claim of fraudulent use of the VISA, and the 31 to 90 day bracket triggers "rebuttable fraud". Only after 90 days will it be unquestioned as hapstance. Now he could not answer for me as to whether the K1 VISA can be concurrent with a B1/B2 VISA. From what I understand, with the K1 VISA, she would have to remain in Thailand till approval, then come to the USA and have 90 days to get married or be in violation. But if she already has a B1/B2 VISA, could she not come to the USA without that K1 waiting period?
As for health insurance, not sure about this. But checking online, it appears that she would be able to apply for Medicare after being married for 1 year. She is 67 years old. Of course, we would have to pay out of pocket, since I do not believe there is any way she could qualify for USA Social Security without working for 10 quarters here. Not that we would need that money anyway, but it would be nice to have at least the Medicare fees covered.
The attorney saw no problems with our plans. He said Florida is a prime destination from many countries for tourism, so her making multiple trips here for long durations (as long as within legal limits) should not be a problem.
For the record, not really sold on the marriage thing right now, just looking at options and the pros and cons. But honestly, I would be VERY hard pressed to find a more wonderful woman. And after all the scammers I had to weed through with the internet dating #######, I sure as heck don't want to have to go through that nonsense again.