I know someone who did this as an easy way of proving where they lived for visa extension and then after many years his wife apparently received a tax bill for the 'rent' he paid her. If you are just thinking about documents for the visa extension then what I do is get my wife to sign a letter/declaration in Thai stating that we live together in the same house and she comes with me to do the renewal. I'm on a retirement extension not a marriage extension and it's gone without a hitch for the last 14 years, in Pattaya and now in Khon Kaen.

From what I understand you can not use a restricted access account for the 800,000 Baht against your visa.

OK, I'm going on what I've been told by a friend with that visa and as you know secondhand information sometimes insn't accurate so as I said please do your own checks.

Totally illegal, nobody is allowed to open a bank account for someone else.

Be aware that the non-OA requires you to have medical insurance with an approved (Thai) company but the non-O does not however it does require you to have 800,000 Baht in a Thai bank to get the 12 month extension. You might be able to get a new non-OA visa each year in your own country based on finances in that country but you run the risk of being refused as they probably don't want to keep issuing them and want you to get the 12 month extension instead then you not only have the need to have 800.000 Baht in a Thai bank but also the medical insurance. The non-OA might be better for a 1 year period but is probably worse than the non-O if you plan to live in Thailand full time. The non-O normally gives 90 days to obtain a 12 month extension but there was a multiple re-entry version that allowed you to stay 90 days then had to leave Thailand but you could return immediately for another 90 days and lasts for 1 year but they may have discontinued that one. Please check with the Thai embassy as I and most people commenting are not experts and just offer advice based on our experience and local knowledge.

Marx Grout The landlord has to do it but if they don't then it's you that gets the fine when you leave, or at least might get a fine.

This really depends on if you are going to get an extension of stay each year and live/retire in Thailand, if so you need to understand the following. The non-O does not require any medical insurance and the normal non-O visa gives just you permission to stay in Thailand for just 90 days, once. There used to be and might still be a multiple non-O visa that allows you multiple 90 day stays during a 1 year period, I came over on this 14 years ago but lots of things have changed since. The non-OA on the other hand allows you to stay for a year (so I understand it) so might appear to be better but although both the visas need you to prove funds in your home country the non-OA also requires you to have medical insurance for the full duration of the visa and I believe it still requires that to be with a Thai company although that might have changed. Note that most travel insurance only lasts for 30 days from when you leave your own country even if it is valid for a year. If you are intending to stay full time in Thailand then you will need to get an 'extension of stay' and although both the non-O & non-OA extensions appear the same (same process) the requirement for the extension is based on the original visa (as I understand it) so if you have a non-O visa then the requirement is having the funds in Thailand but the non-OA is having funds in Thailand AND the medical insurance. So if you are going to get the extension then I think it's better to enter on the non-O visa so you are not forced to have medical insurance every year to maintain your visa status but that's not to say that I think you shouldn't have medical insurance as I do but with the non-O visa (and extension) you are completely free to choose how much cover and with who where as with the non-OA you HAVE to have the insurance and it has to be for a certain amount and with an approved company. I'm no visa expert so please check what I've said before making your decision, this is just my point of view from someone who has lived in Thailand for 14 years and has friends with both non-O and non-OA visa (extensions). Sorry it's so long

My guess would be that if you don't have family that you will be staying with when in Thailand and have no plans on what to do or where to stay then you're not likely to be a tourist so don't meet the requirements of a tourist visa. All you probably need is hotel booking, sightseeing plans etc. Probably even just a list of hotels and some details of what you plan to do would do (go to Pattaya to get drunk & laid might not be a good plan).

Aniket Dasgupta I'm not so sure it is impacting the 'genuine tourists' as all the people I see complaining about the way Immigration is operating appear to be long term 'visitors' not what Immigration (and me) think of as tourists. If people are coming into Thailand on a 60 day exemption, extending that to 90 days, leaving for a day or 2 and then returning for another 60 day exemption and trying to extend that by another 30 days so in effect are living in Thailand for 180 days with just 1 or 2 days outside would you call that a genuine tourist?

as you appear to be a real tourist and not trying to live full time in Thailand I would think that you should be OK but as you said it does depend on the Immigration officer at the gate but be polite and have all the necessary answers ready and I think you won't have a problem. By the way I'm no expert but do watch the local expat news a lot.