Can I get a residency certificate from a TM 30 if I'm staying in a hotel to open a bank account in Hua Hin?

Yes

You can also own the land if you become a Thai citizen. Apply after 5 years not that hard to do

Yes you can

Thai bank account opening MINIMUM pre-requisites:

*** have a Longterm visa, like a 90-days Non-Imm-O visa type, an LTR or Non-O/A

*** you need to be properly registered per TM30 Online System at your accommodation.

It is a big question if Immigration is willing to issue a certificate of residence on a TM30 from a hotel. This is solely Immigration specific , so in Hua Hin you need to ask them asap!

*** visit Immigration and ask for the “certificate of residence”. Immigration in this document will ask the bank explicitly to open a bank account for the applicant.

*** have a Thai mobile number and the SIM-card registered to your name and passport number, show the receipt from the phone shop.

*** your passport as a valid document of identification.

Some banks will ask you for a second piece of valid identification, like your home country driver’s license.

*** a work permit (only if applicable – it is NOT a mandatory requirement!)

Here a list of NOT commonly needed requirements, but that can get asked from over-zealous bank staff:

*** They might tell you that you have to be married to a Thai wife if you want to get a bank account opened.

*** a rental contract - actually irrelevant- but it is okay if you got one, or if you got a blue housebook indicating ownership of a condo.

*** a third (!) piece of identification (check above)

*** a mandatory life-insurance or accident insurance the bank offers you for yearly 5000 Baht (they love to earn a sidekick)

*** your foreign Tax-number or Social Security number (which would be okay so far, why not)

Try several branches of different banks, you should find one that opens an account for you under the minimal requirements. Sometimes it takes a day or two of running around until you find a bank willing to help you.

I don’t recommend Bangkok Bank. Better get a Kasikorn or Siam Commercial Bank account. Other good banks are Khrungthai and Krungsri

In case you consistently meet bank staff who resist and pull out of their noses random requirements, use the service of an agent. In Pattaya for example, you can get a Thai bank account opened within 2 days for 5000 THB. In Hua Hin I would check around, there is an agent by the name of "Anne"

Certificate of residency should be fine with the hotel tm30, or just register at your wife's family house and get her to take copies of the house book to immigration. Enjoy buying your wife a new house that you will never own.