Webrocket,
If Steven is gay, do you reckon it's likely that he would socialize in Vegas ? But, I can't quite see him leaving town with a gay lover. He is, quite honestly not that young, totally broke, and seemingly has a very hard time supporting himself. Which would mean that his lover would be financially supporting him, and for how long in the future ? Doesn't make much sense. But, I do feel anything at all is possible in this situation. JMO
Assuming he ran off with a guy, I assume he would have had some means to support Steven. How long into the future is anyone's guess. Hence the passport may have been for future possible use.
Youth is all relative. He was certainly no 18 year old but to someone considerably older, Steven seems like a nice clean cut guy who was not a product of a club or drug scene.