I think building a new character type out of existing abilities is really interesting. One thing that I think makes it work really well is renaming those abilities to get across what it represents for this character.
For example if you renamed "A Little Something on The Side" to "Cash Games" or "High Roller's Table" it would be more evocative of the character earning money by gambling on their downtime. Similarly, changing "Foresight" to something like "Hedging Your Bets" would more be in keeping with the theme of the playbook.
There's a Forged in the Dark game called Sea of Dead Men that has some really good examples of how changing the name of an ability while keeping the mechanics the same can make it feel very different.
One other thing I would say is that I don't think "Like Looking In To A Mirror" belongs on a gambler playbook. A gambler needs to be taking a risk, even if it's a hedged or calculated risk, and there's know risk if they know for certain whether or not the other person is lying.
Viewing post in The Gambler jam comments
I thought about changing names, but then that seemed a bit like stealing? But if that's like A Thing other folks have done, I'll try it w/ Gambler v2!
& I see what you mean about "Like Looking Into A Mirror", I'll look things over again & see if anything fits better or maybe try to make a new ability!
Thank you for the feedback!!