1 As described, profile with MB, dollar signs etc.
2 Thai including รับงาน (accepting work) & variations of that, particularly abbreviations (Be careful. รับ=accepting, so when used alone, this indicates his sexual position, as far as I understand)
3 If you are visibly over 50, have a profile picture and he's still talking to you, there's a good chance he's a money boy. But not certain. If in Pattaya, a very very good chance.