Yes. But again, be aware that there is more then one company offering this service. And a lot of them issue not real tickets. Indeed some do, but if you have the wrong one you are screwed.
I used indeed one of these companies before. But you must be sure that the ticket is a real one, as 80 % of these tickets, are not a real one, or not valid at time of travel. A cheap company to Cambodia, Penang, other nearby country are very cheap. No need to register luggage or extra, as you are not using the ticket. Some companies check this. I even, was almost denied with a real ticket, agent stating it would be fake. I gave him a hard time to check it then.
Just see that the flight company, not give trouble, as they not take in count the extension. So see that you have a cheap flight out, after 60 days. Please not say, not had any problem with this, many did.
Would all banks ask now that certificate of residence? As a long-term visa in your passport not tells it all, always go for everything to madhouse in Jomtien. Or issue a card, everyone can read, that you are resident, or accept drivers license
That is annoying. In Chonburi - Pattaya, no need of certificate. Is also ridiculous, as long you ve the transfers every month. I did provide them with a contract, but they never ask for it.
Should be on your statement. Normal international funds transfer is enough, but should be there. And verify this every month. I did same as you want to do.
I had the 800.000 method first, then changed to monthly income. Jomtien immigration was fine with years statement, where monthly transfer was visible. No affidavit needed, I gave proof, where it came from. But not one transfer in that year can be skipped, or done after the month, it is supposed to be in your account. Not used agency.