1.) I know 100% that when you send bitcoins from legacy Address (P2PKH) then your public key gets revealed in transaction signature So this is also true in case of other Address formats (P2SH and P2WPKH) ?
Yes, your public key is always revealed. Since nodes need your public key for verifying your transaction, you have to reveal it.
The address in question is a multi-signature address and has been generated using three different public keys.
I don't know how, but it should be possible to derive all the three public keys from data of a transaction made from that address.
3.) How can i hide my public key while still Re-using the same address for spending? I suppose it's possible because the address i mentioned in question 2 is able to achieve that.
I don't see any reason for hiding the public key and I said above, you have to reveal your public key whenever you make a transaction.
If all 3 address's types reveals public key when you send bitcoins then what's the additional advantage of using newer btc address types say Taproot one's (except the lower fees benefit) ?