a state chain connected to Lightning

even this is generous, with Lightning it's using trusted swaps... it's literally a shitcoin exchange

There is no unilateral exit [to bitcoin]

If you use it as an on-chain wallet, it's possible... but it's also pointless as an on-chain wallet, the real scam is in the lightning affinity

Is Spark actually Bitcoin?

Definitively no, it's a closed network with a central coordinator, the opposite of Bitcoin being an open network with no central coordinator.