you need a job offer and paperwork from the business for the visa and then you need to actually be in Thailand, have all the same documents + more then go to Work Permit office with your employer
depends on what you do for a living, for example, a legitimate teacher working in an international school is being paid far more than most teachers in the west and that's without considering the vast difference in the cost of living.
You need a non-b for which you need a legitimate job offer, but you aren't getting a job offer as a barista or someone who just serves the coffee unless you have a specialist skillset that is hard to come by in Thailand as it's a reserved job... Some goes for working in a hotel, if you're not offering a specialist skillset you aren't going to get a job offer.
If you phone is locked to a carrier you can pay around $30 and get it internationally unlocked. Takes a few seconds. The next phone you buy make sure it is an international model, costs a little bit more but you don't have to mess around and can be used in any country with any SIM card.
Relatively easy so long as you can show ample proof for reason to return. (For proof we showed that we have 2 businesses here, a house, 2 condos and take care of her parents and sisters children.) Once you've gotten a visa, every visa after that is like a walk in the park from that point after (so long as you do not break the rules of the visa, such as overstaying)
I would avoid agents if you can, they can't actually help you get the visa, they are just doing your paperwork and giving you guidance which you can easily obtain from pages like this.
I've been told by different IO I know that on re-entry and extensions you will need to provide both proof of funds and reason to be here and booking a course for a couple of days is unlikely to get you entry.
when getting the yearly extension your TM.30 must show/have an expiry date that matches your rental contract ending. Example contract states 1st June 2025, TM.30 Check out date must also say 1st June 2025. If you rental contract ends 1st June 2025 but your TM.30 check out date is say 2nd February 2025 they will make you file a new TM.30 (this is how I understand the post)
You might want to check with your local immigration if they will accept the 12 month method without an affidavit from your embassy, and some now will only accept the 12 month 40k deposits method if you are working inside Thailand.