Hey thanks for trying it out!
The NPC's are meant to be a balancing factor on the player, but in your recording it seems you got a lot of difficult NPC's waayy before you had a chance to establish a build. For instance, the Cowboy (meant to be a late game boss type) shouldn't have spawned at that heat level. That's my bad and I'll look into addressing the bug.
You are correct in that they are supposed to be a negative for the player. Craps has a very "fragile" balance, so once the player starts increasing a certain bets payout, or decreasing the chance of a 7, they can start feeling very safe, which is what the NPC's are meant to offset. But I do see how re-rolling is frustrating, especially when you have nothing to combat it. I think I'll add some stickers and special chips to give players control over that, which could help with that feeling.
Thanks for playing, and the recording + critique, it's very helpful!