I gave you the first accurate answer, scolded the guy who said Google it and now I'm a keyboard warrior? Okay then. But you are still welcome for the advice
With UK passport you get visa exempt for 60 days in Thailand (although rumours keep swirling that it may return to 30) 45 days visa exempt in Vietnam and 90 days visa exempt to Singapore. Just make sure you have proof of onward travel in each case .
you mentioned governments and cartels. You know everyone else pays just 50 baht for withdrawals? They've just had a chat amongst themselves to target your cards with the 250 bhat fees to enrich themselves