Take for granted that I (your 50 years old parent) have near zero knowledge about technology and I just won't use my own wallet and what not.
The best, to my knowledge, decentralized anonymous crypto exchange is bisq [0].
The "unable to recover" feature is central to Bitcoin by design, because that way it cannot be censured or otherwise manipulated by non-majority actors.
To finish, Bitcoin is not the most technically sound cryptocurrency around. It is a historically pivotal idea and implementation, but it's details are not the future of cryptocurrencies.
2. You should anyway only use proper exchanges, then it's like using your current bank.
3. You don't have to use your own wallet. Cryptocurrencies gives you the opportunity to do so, but it's not a requirement.
Lol, given these conditions and unwillingness to change them you definitely shouldn't use it at all. Just forget you ever heard about it.