According a report from a visa agent, internal BKK bank regulations currently prohibit opening accounts on tourist visas because of regulatory issues, but there is no actual legal prohibition (i.e. they're not prima facie illegal). There are issues with accounts which don't match registered mobile numbers etc. but that's a general regulatory issue, not one specific to tourist visas
What was in the news was their closing accounts connected to scammers which had been opened using falsified documents. If there's been an order that the banks have to close accounts opened on tourist visas, kindly post a link to that article
It seems that what they want is a verification that the passport is genuine, which isn't the same thing as providing a certified copy (although arguably, the Embassy won't provide a certified copy of a fake passport) 🤔
People have been known to build their own houses. The police pass me regularly when I'm sweeping leaves or something outside my house. It's a myth. Doing work for others is the problem and where people come unstuck as they think doing a mate a favour is ok. Legally, it's not, even with a work permit
Examination costs are negligible here and UK. If you need glasses, then get them wherever is most convenient. The point is that there isn't a massive cost difference for most people in most circumstances between UK and Thailand. For me, it was a bit cheaper to get at Specsavers overall because I was taking advantage of their promotions and got a spare pair