You might have to prove the money is legit. But if not locked away from a signed agreement, they have no rights to just hold your money for any time. Let alone months.
Talk to them, and question the legality of them freezing your funds.. I don't see how a bank can legally do that, if you didn't agree to some kind of locked account (high interest/investment/etc).
If you are not the source of any wrong doing, following the agreement you have with them (terms and conditions) there's absolutely no way they can just hold on to your money for 90-120 days without letting you access it.
You can put in more than 90 days, but you won't get more than 90 days. The visa is valid for 90 days to use, and will get you stamped in for 90 days when used to enter Thailand. Regardless of what you put in that field.
And yes you can put in your wife's address if that's where you are going to stay.
that makes perfect sense. Depending on where in Thailand, you might be able to get the visa without leaving Thailand. Some immigration offices can and will sell you the visa. Others won't or can't. If that's the only reason for going home again, check first at your immigration office. You might save a trip.
if it's possible to each access the same account, with the app, why do you need separate QR codes and credentials? It's the same shared account. It doesn't need a unique QR for each user. It needs a QR to identify the account. Why wouldn't it work for you if it's the same QR and credentials? Any transactions will be on the same account anyway.
the bank have absolutely zero authority to just decide that it has to be 4 months.. The law say 2 months for marriage extensions which also requires that letter.
for retirement extension purposes, it's 800K 2 months before applying, 3 months after applying, and not below 400K the rest of the year.
For marriage extension purposes it's 400K 2 months before applying. That's it. Although there are reports of people in the recent weeks being told by Bangkok Bank specifically that the 400K will be frozen in the account for also 2 months after.
I don't think it's a national thing, and I also question the legality of the bank just freezing your account like that without any wrongdoing from your part.
They don't want people trying to live here long term on visa exempt/tourist entries.
If you maximize even one border run with a 60 day entry and 30 days extension, you've already spent 180 days in Thailand.
They are very likely to question you about being just a tourist at that point.
On the other hand you can enter many times a year without ever having any issues, if your travel history shows you are in Thailand for shorter periods. Not maximizing your stays and extending them.