Yes, definitely don't put off for tomorrow what you can do today. You have no real control over how long some things take so you have to move swiftly on the things that you control. For instance, if you plan on using Wise set up the account now.
Oh, I see. This is my understanding of the process. Assuming you're going for the retirement extension. Assuming you're arriving on a TR. Assuming you're in Phuket (other provinces similar but not identical).
As soon as you get out of quarantine you want to open a bank account immediately. Try on your own, if repeatedly unsuccessful you may need to employ the services of an agent to get you a bank account. Bangkok Bank is best. Get 800,000 baht minimum transferred into that bank account as soon as possible (Wise can be a good way to do this). Go to immigration and apply for a Non-O for Retirement when you have as many as 45 days left on your initial permission to stay. At that point, you need to demonstrate that you have satisfied the financial requirements of having 800,000 baht minimum in a Thai bank account. They will accept your application and then it may take as long as 30 days for them to approve your application. Up until you receive that approval you will have under-consideration status, meaning you will be able to stay in Thailand. If approval is granted you would get 90-day permission to stay. 45 days before that permission expires you would have to apply for a retirement extension of stay (requirement being that you must have the minimum balance of 800k in the account for 2 months prior to your application). If granted on the date of application you will be told to return the next day and pick up your passport with one year's permission to stay stamped in. At that point, you're good for a year's stay in Thailand. You cannot let the balance in that account drop below 800k for the next 3 months and thereafter it cannot drop below 400k for the rest of the year. 2 months before you apply for your next year's extension balance must be above 800k again, and so on.
I recommend doing everything as early as you possibly can. Some problems can be solved with time. If you do things at the last minute it can be very stressful.
So to get back to your question, is it really 30 days for being under-consideration? I don't know. In a sense, it doesn't matter because if you have the under-consideration status you can remain in Thailand, and to my knowledge approval is basically Pro-forma. In other words, they won't even accept your application for a Non-O visa for purpose of retirement if they think there's anything wrong with it. The expectation is if they accept your application you will get the visa, you just have to wait out the under-consideration period.
I have not left or tried to re-enter Thailand during the Covid-19 era so the information I might have comes not from personal experience but from reading information online.
Does it take up to 30 days for Thai Embassy Malaysia to process an application for a TR?
Seems unlikely to me it should take that long, but I don't have any personal experience. I would guess it should take something like 3 business days, but again, just a guess. Maybe they're talking about the whole process up to and including the COE? Still seems like a long time.
Re Covid-19 extensions of stay. Earlier on in the pandemic immigration was very strict about granting this extension. You had to have a letter from your embassy requesting they give you one. That requirement dropped some time ago. It now appears that they give one to anyone as long as they request one and pay the 1,900 baht. You do have to fill out a form that indicates why you don't want to travel but as long as you check one of the options you seem to get the extension. A friend of mine got the covid extension very easily in Phuket, but she was already on a covid extension. I guess there are no guarantees, except it seems easier to get now. The last date they will be sold is 30 May, unless that date gets extended again...
I see what you mean. As far as I know, that's not a general requirement for the TR, but when in Malaysia you have to follow the rules of the Thai Embassy in Malaysia. One possible workaround would be to book accommodations through a site like booking.com which I believe allows you to obtain a booking that can be canceled without incurring any cost before you check-in. A similar strategy can be used with the ticket out of Thailand requirement. Book a ticket out of Thailand that can be canceled without incurring any cost or purchase an inexpensive ticket that you may or may not use (maybe Bangkok to Kuala Lumpur, for example).
The major difference between TR and Visa-Exempt entry is that (including the 30-day extension you can obtain with either) the first allows you to stay for 90 days and the second allows you to stay for 75 days. Both can be used as the basis to apply for a Non-O visa inside Thailand. An example of that process at least in Phuket:
A second difference between TR and Visa-Exempt entry is that TR does not generally require a flight out of Thailand while a Visa-Exempt does. My understanding is that this is mainly a requirement enforced by the airlines at check-in/boarding rather than a Thai Immigration requirement.
I'm not familiar with needing paid accommodations for a TR visa, apart from obviously the requirement to book ASQ for your quarantine. But since the Malaysian Embassy is where you will presumably get your TR you may have to follow their guidance on this matter.
As far as I know, there's no need to prove (and pay in advance) for lodging during your stay (like there is with the STV).
That said, due to covid-19 you may be asked to tell officials where you will be staying although I don't know what if any proof is needed. For example, if you were to visit Phuket now they insist that:
"All arrivals from red zones must install the MorChana app on their phones and share their location for the duration of their stay in Phuket, and must register their travel details through the
****************
web portal. Those unable to register their travel details online must report themselves to an officer at the municipality or a local administration office."
1. Yes, you don't have to specify your itinerary or lodging.
4. Yes, for 1,900 baht you can extend your Tourist Visa for an additional 30 days at your immigration office.
At the moment you could even get an additional 60 days with a covid-19 extension which are being sold at your immigration office up until May 30. Possibly they may even be available for sale beyond May 30 if that program is extended as it has been a number of times already.
I'll leave 2 and 3 for those more knowledgeable about the STV, although I believe it is not possible to stay past 30 September 2021 on the STV as that is when that program is scheduled to end.