You can apply in Laos. Vientiane or Savannakhet. They use a hybrid system where you apply through the evisa portal but go to the embassy/consulate to pay in person.
Bangkok has been pretty much unaffected by this bar a few places.
Yes there has been the issue of the SAO building collapsing and loss of life, which is horrible and a few other issues with some buildings needing inspections but overall fairly unscathed if that’s a term that’s “allowed”.
Visa offices around the country typically interpret “rules” their way. The “official” rule is that you need 500k in a “bank account” for at least a month prior to applying for the extension. If Hua Hin is interpreting that as “in a Thai bank account” then so be it. There’s pretty much not a lot you could do about it.
Do what 90 or so % are doing and bounce rather than extending.
No visa grants you entry in to Thailand. That is up to the immigration officer that gives you permission to enter. What it grants you is the right to stay for x number of days if allowed in to the country.
Where a visa may help is that the IO recognises the fact that you have a valid visa to enter and would probably be more likely to grant you permission to enter based on that.
No visa (or exempt) entry is a given. It’s up to them. If they feel you are doing something to abuse the system then they can deny you entry. Very very rarely would happen for an actual visa but it has and could.