To give some background, my short story is written from the perspective of person K. His school friend A (they are both in their mid-twenties now) invites him to stay in Vegas for a short time, and K accepts the invitation, as he is taking a break from university to work on his painting.
Both characters are struggling with personal demons, K with the death of his parents while A is struggling with a gambling addiction which has isolated him from family (this isn't immediately revealed). And part of the reason A has invited him over is to take advantage of him financially, as K's family has never had problems with money. The idea is that A has lied to K, saying he works at a casino, when in reality he is spending all his time there gambling. In the story K catches him doing this and there is some sort of confrontation. I also want to explore K's changing perception of Vegas, from the riches and luxury to the poverty and suffering.
My question is what kind of scenes would be good to include? I want the reader to care about the characters and their problems by having some backstory (e.g. K and A having conversations) before introducing conflict, but I don't want to include unnecessary details. Ideally, the characters would be in some kind of danger/dilemma, e.g. shady loan sharks coming after A, but I don't want to have violence/action for the sake of it. One route to explore could be K's painting (it reminds him of his late mother and brings out certain emotions).
The big question is whether the short story could work well without any extra characters.
Another thing is how to maintain tension throughout the story. Would it be anti-climactic if once K catches A at the casino, the characters fight and then finally connect over their problems and help each other? I don't want all the stakes and tension to be lost too suddenly if that makes sense.
A might be stealing from K so I'm wondering whether something more dramatic with loan sharks, violence, etc would work better. And whether A redeems himself at all or chooses to go on a more self-destructive route.
Thanks for all your help, I appreciate this is quite a lot of info.