I have experience in getting questions because of showing accommodations in Samui. One officer took me out of line and handed me over to another commenting something about Samui (my Thai is not great).
Your assumption that they do not care where one goes is not correct.
And as I have understood from many friends one is also very much more likely to get questioned or denied when many visas are in the passport. I never heard of anyone getting questioned or denied with a single visa in the passport.
Okay, I was intending to bring the money anyway, what about the documents? I guess I mostly want to know whether I need a flight out or proof of accommodation, and if accomodation, for how long?