BBM snipped out picture
The questions you ask are really important, IMO. To begin with, how dare he show up on this trip expecting all expenses to be paid for when SWM didn't seem to know anything about treating him to a luxury vacation. Then, after already living it up on her dollar in another hotel the month before, he arrives and expects SWM to pay for an expensive room for him and HM!!!
It seems either Heather misled him to believe it was cool with SWM for him to show up, and not even have enough money, or they could force her to pay. The other possibility is that they did have a premeditated plan and unless SWM cooperated with things going their way, they'd overpower her. TS was a dreamy opportunist and he was hungry for wealth, luxury, and the easy life, but TS just didn't seem on the edge of becoming a murderer for it, JMO.
Maybe, but MOO, I think Heather gave him the ideas and encouragement to get involved in all of this. I'm not sure yet if TS had any intention of actually killing someone, but I have less doubts when it comes to Heather.
Thank You for bringing this up because, as I've said before, I don't know what TS thought his role was on this trip and it makes a big difference.