you can stay five years on the visa if you just exit and re-enter enough times. Most don't want to be locked inside anyway and will renew their entries naturally. You may need to hop across a border occasionally but that isn't a big deal. You can live in Thailand with this visa for five years, it's not just a 180 day entry and then stop like you suggest.
Work two more years, your pension will be above 65k, and you're out of trouble.
Besides, 65k is not much to live off. They require it as a minimum, but it doesn't mean that you necessarily want the lifestyle that this amount restricts you to.
like this guy. He studied for it. It's his profession. Now some idiot (which is you) shows up here in the topic to tell him he doesn't know anything. It's quite hilarious, you know.
no, YOU don't know. Keep such claims with yourself. Tax professionals typically do know what they talk about, they studied for it and they stay up to date with rules.
Very strange that someone tasked to give you proper advice on Thai visas advised getting a DTV of a Thai child or girlfriend category. These categories do not exist, and that should be known to many, if not to those tasked to advice visa applications. Are you sure that this really happened?
I don't know how remote work really works, obviously you wouldn't work in Thailand but your job would offer you substantial time IN Thailand while also being employed. Could that be what she meant?
Otherwise, just get the custodian visa. There's a visa category for that.