New to P2P markets, I have some questions

I've been buying Bitcoin via centralized exchanges and transfering directly to my hardware wallet but according to some of these CEXes it is now a requirement to make a video of MY personal wallet/holdings to prove ownership (or some bullshit) in my country before they'll let me transfer funds from my bank. To me this comes across as a poor attempt to do KYC, which I hate with a passion.

I'm new however to P2P alternatives and I have some questions that maybe some of you are willing to answer.

1. When I initiate a trade on an app like Bisq where I am the buyer my understanding is that I have to transfer funds to the seller (through various payment methods). The seller then has to confirm that the funds were received, after which a multisig transfer of Bitcoin will be initiated by Bisq.

What happens though if the seller does not confirm the arrival of my funds? Will there be any recourse for me to get my funds back, or do I simply have to trust the seller?

I know the same can be said about centralized exchanges in the sense that I have to trust them with my money (albeit temporarily) but I am wondering if maybe there is a way on the protocol level to have some sort of middleman/smart contract type functionality that still allows for fiat -> crypto conversions.

1. I know nobody can answer this with 100% certainty, but how likely do you think it is that Bitcoin that was obtained outside of KYC-enabled environments will be somehow marked as such and could in the future (if/when we have mass adoption) be rejected by retailers/institutions we depend upon? (e.g. for day-to-day needs)

For example, when retailers I depend upon for my day-to-day needs accept Bitcoin through some third-party (I think this could be enforced by governments, sneak in through misinformation, etc) and this third-party would only allow for coins that have been obtained via CEXes with KYC, they would theoretically be able to reject my payment because I have obtained my coins outside of KYC enabled environments.. right?

Thanks.