A cash advance is taking physical cash out with your credit card at an ATM or bank teller. Making an online purchase (which depositing money into your Kalshi account is) is therefore not a cash advance.
There are many kinds of "cash advance". You can't buy lottery tickets on a credit card (or in jurisdictions where you can, it's a cash advance). Credit cards also treat things such as buying dollar coins online from the US Mint different from a normal transaction.
In Australia any sort of gambling payment on a credit card is treated as a cash advance. If you use PayPal on top of your credit card, the credit card company still manages to introspect it and apply a cash advance fee.
Not necessarily, I mean if you buy a in-game item or currency that wouldn't be a cash advance so with this they could just say you bought $20 worth of credits and since you're buying credits that could be considered a good.
https://gosunward.org/articles/cash-advance-on-a-credit-card...