The OP asked for a "warm but cheap" place in SE Asia. Does Singapore qualify for that definition in your opinion? If not, then it's irrelevant to the thread.

One visa per year will raise questions? 60 day tourist visa plus 30 day extension.

Great post about a great city. Very concise and relevant and on point. Al I could add is the vibrancy of the city. E visa for USA Passports is $25. A quick trip to Cambodia by bus with Visa arranged by Bus for about $50 will solve your Vietnam Visa stay issues.a fun trip too.

Your money will probably go farthest in Indonesia, and you'll get pretty good value for it. Given you don't seem to have much experience living in Asia, touristy but comfy Bali might be just the place for you, probably somewhere around Ubud. Indonesia's a bad choice if you might need good healthcare, though.

Finally, don't ignore the earlier comment about walking. If you're a drive-everywhere type with a foot problem, then Asia just about anywhere may be a bad fit for you.

Your reply was

'anywhere else' in relation to Asia includes anything starting from Turkey and ending to Papua.

This is important - with the limited mobility and requirement to get from place to place on car/taxis cost of living most likely will increase substantially.

Recommendation about Arizona should not be dismissed as trolling. It might will be the best recommendation with the set restrictions.

Welcome to Vietnam holiday. Nha Trang Beach, Da Nang, Hue, Ho Chi Minh, Phu Quoc is warm. You should try to live in there.

If walking is an issue, I recommend Da Nang for various reasons. The traffic is nowhere like HCMC and you can get around easily by renting or owning a motorbike. The municipal government laws are more relaxed there, hence more Western like than other parts of Vietnam. You can visit Hue and Hoi An while living there.

Bali is more expensive than many of the other places being considered.

Housing is likely your biggest expense. If you can rent a house or apartment for $300-400 a month, then $1500 per month will probably keep you comfortable.

I've been to every country mentioned, and never had much of a problem communicating. A simple phrasebook works well, along with a smile, and maybe a translation app.

I think Bali or Thailand would be the easiest. I think Thailand gives 60-90 day entry, so probably the easiest. Getting around by motorcycle, taxi or Uber is fairly affordable. It can be quite hot during the day, but if you come out at night, it's not bad.

Singapore is fine for a short visit, but it gets expensive quickly, and a bit boring, imho. Malaysia for a week or two, could be good. Vietnam might work out, but I found less English there than most other SE Asian countries.

My first visit to Indonesia was in 2004, for a month. I stayed in Bali for most of it. I spent about $25-30 per day, including food/housing. It was one of my best trips, ever.

A friend of mine did 1 month in Thailand with his girlfriend for around 2000 euros and i know it was not on the cheap side of travelling, he likes his food and his comfort

If I was in position as OP, I would do 1 month in Thailand, 1 month in Vietnam and 1 month in Cambodia or Malaysia.

Every year or just for the first year to figure out what he likes?

Hopefully the OP will come back and give the thread some direction. Many good posts too..

It depends how adventurous the OP is. If he likes the same old over and over again he can commit to one place.
If I haven't been to SE Asia, and I had to make decision where to stay for longer period of time, I would definitely stay at few places for couple of weeks to figure out which place I like the most.