The Bangkok Bank branch that would open an account for me without accident insurance was the Boonthavorn branch. I tried several others and they insisted on the insurance, so I looked elsewhere.
I am 6'3 and have flown with different airlines like Qatar changing at Doha and it's a good experience, the legroom is sufficient on these longer flights.
If you are worried about food buy some extra in the departure lounge, there's always sandwiches and crisps.
I quite enjoy splitting the journey, but would not want longer than 3 or 4 hours. Depends where you live I guess, I am from Leeds so it's a chore getting to London for a direct flight.
did you have a visa when you arrived or did you arrive without a visa or visa exempt. If so that could have been the problem.
I agree with John about the O type visa inside Thailand, seems easier and a better option you.
When you come next time get a 60 day visa online that can be extended by 30 days.
The bank account opening is definitely the most difficult part of the visa process, but as John said try several banks. I found Bangkok Bank to be the most accommodating, but I had to try 3 different branches until successful. They might make you buy some accident insurance as a sweetener!
Once you get this, you transfer the 800,000 and wait 2 months to apply for the retirement Visa.
You need to get the requirements for this from immigration, fill out the form, provide original and photocopies of everything, some recent passport size pictures and pay the fee.
There are lots of very knowledgeable people on here to help you through the process.
When you have this fly into Thailand and open a bank account in your own name and deposit 400,000 baht into it. Wait 2 months then apply for a spouse visa.
Don't use an agent as it is expensive and you can get through the visa process without an agent, just provide the information and documents requested by immigration.
The difficult part is opening a bank account, but shop around. I used Bangkok Bank, but had to try several branches to find one that would open it. Go smartly dressed, be polite and take your wife and her house details.