My experience has been that most Thais are friendly and very entrepreneurial. They will take care of you regardless of the colour of your skin. I shall not worry about it. Money is money and as long as you’re interested to buy, they will sell! Having said that, you still need to be vigilant with those usual tourist traps, which are not unique to Thailand. I have never been truly comfortable hiring a Thai taxi, particularly one of those at the airport which drivers invariably "forget" to turn on the meter unless you "remind" them or taking the most direct route.

I have stopped visiting TripAdvisor for some time. That web site is dominated by budget travellers whose definition of “best” generally means the “cheapest”. Most probably couldn’t afford to go to the Dome and therefore wrote silly things about it. A little bit of sour grapes. IMO, you get what you pay. You frequently read posts about where best to exchange money because the posters were about to save an extra US$1 or 2. Hotel B is "better" than Hotel A because it is cheaper, without differentiating that Hotel A is 4-star rated whereas Hotel B is 1-star or even better described as a hostel. LOL.

The Dome is probably worth at least one trip for the experience although I do not think that it’s good value for money. It’s one of those things that tourists do. Once is enough. "I've been there when I was in Bangkok." When you visit Paris, will you be satisfied with just at the foot of the Eiffel Tower, or will you be willing (subject to affordability, of course) to pay the extra to buy a lift ticket to go up to the observation deck?