Sandy... I've only placed a bet on 2 horses in my life. After being badgered by my work college back in 1962. I give him one pound to put on a horse called "Jackman". Monday morning he made me swallow my pride when he gave me four pounds and ten shillings in winnings, he then told 200 people who worked in the factory how good a punter he was in jest, and he told the story over and over again. My next experience was about 1976 at the final of the Interdominion Trots in Perth W.A. I put $5 on a horse called "Down and Out" in a supporting race reminiscing my plight at the time. Lowe and behold after a bad crash of several spiders in the race "Down and Out came out 1st place and I got $75 back including my money back. I have never bet on a horse in a race since. I may be regarded as a very successful punter. I got 10 times my money invested back, and I've never had a bet since. 2 horses and 2 winners. Good luck.
Perhaps you should learn how to bribe the police before starting a gambling syndicate in Thailand. Not so common now or else spend your time in Thailand as a guest of the "bangkok hilton" commonly known as a prison. No reflection on the loverly hotel known as the real Bangkok Hilton spelt with capital letters.
I have now been to Thailand 15 times in just over 13 years. Two of those times were O retirement visas from the Thai Embassy Canberra in Australia, all in order. The other 13 times on a Tourist visa or recently on visa exempt twice. Although I have had a return ticket to Australia each time I have never been asked if it is so on all my trips to Thailand. Even when I have indicated this to the Immigration person they have indicated they did not want to know.
There are better options available if you are over 50 y/o, Like an O retirement visa from your Thai Embassy from your own country, it is multi-entry. The 1st years of that visa once granted you can come and go as often as you like in Thailand. At the end of that year, you can arrive in Thailand just before 12 months and get an extension for 12 months. Then you will be no longer able to renew that extension, you can not get an extension on an extension.
You will need a police report from your state PD and a medical showing you have no social disease. And about US 200 and prove you have Bt800.000 in a US bank about $25,000. Only original Bank statements are accepted. All you need is documents signed on every page by a JP and 2 extra full sets of photocopies. It sounds tough but once done 2nd time OK. I know, bean there, done that? This way the Bt800,000 or about US 25,000 is still in your bank account, there are no conditions on what you now do with that money once the visa is granted, spend it, it's yours.
Most travel travel or health insurance worldwide have anywhere between 70 and 90 pages of fine print conditions, they are nearly all the same. When you take out a policy you do not have to state what your health conditions are, the insurance companies will accept the risk SUBJECT THE CONDITIONS IN THE FINE PRINT. When it comes to making a claim, the accident part of your policy will be likely paid but the medical part now will often reveal if your illness is pre-existing when you get treatment. I do not know of any health insurance company world wide that will include any pre-existing coverage for a client with any serious health conditions. I was in the business some years ago selling the stuff for a large Australian insurance company and processing claims. Those who did or do have complete indemnity and unconditional cover have likely gone broke.
This is highly illegal in Thailand but usually pays off. Risk being banned from Thailand if corruption is used??? Risk it if you like. Why not apply for your O retirement visa in your home country e.g. Thai Embassy in Canberra. Once you qualify there is no restriction upon receiving your visa you can then do what you like with the Bt800,000 that's in your Australian bank when you do get to Thailand and it can be good for 2 years. It will be a multi-entry entry Thai retirement visa visa. You need a medical, a police report and an original statement from your bank showing you have the Bt 800,000 in the bank, not photocopies only original bank statements also an application form all signed by a JP and about Aus $300 at the Thai Embassy. Canberra. It took me one week from Perth Australia 2 times. Look up the Thai Embassy website. It's available from most countries Embassy.