Visa exempt entry is not guaranteed. Especially now, playing the game and not being a “real tourist” can lead to you not being granted entry at immigration.

This leads to the recommendation to get a visa. Am I correct that a visa is also not a guarantee to entry. What would lead to entry not being granted at immigration if you had a visa?

Caveat: if you are a tourist with more than one trip annually, what is the difference for entry between visa exempt and SETV?