You have a lot of questions and they all stem from a lack of basic knowledge about what you are dealing with. Master private keys (xprvs) are what you need not master public keys (xpubs). It is not possible to derive the master private key from the master public key. It is not possible to derive any private keys from any sort of public key.
Your wallet is a multisig wallet so you need signatures generated by multiple private keys that can only be derived from the master private keys. Without them you can't spend your bitcoins.
ThomasV or anybody else can't help you either. Bitcoin is not a bank.
Initially, I tried to create a 2FA wallet and realized that it wasn't supported by the electrum mobile app. Therefore, I went the route with multisig-- and without my knowledge and carelessness-- created 2 cosign wallets without proper documentation. You are certainly correct, I lacked the knowledge of how the functionality of multisig wallets. And made a really big mistake, but not properly documenting the seeds/xprv values, when creating the 2 additional cosigners. That is probably the root cause of my mistake, and not knowing/realizing it
not a good day for me and an expensive mistake.
However, money can always be replaced and time can not (which I have spent almost 48-72 hours around the clock trying to recover). Therefore, I maybe at a point where I just leave all the broken pieces on the ground (and funds in my wallet), walk away a wiser man.