Does 'Mixing' in bitcoins really add up protection to my bitcoins? I was researching on simple ways to protect bitcoins without using unknown/untrusted software or solutions. It took my attention to 'Mixing' in the bitcoins with a friend's bitcoins and transfer back the same amount of bitcoins back to my wallet. I understand that it will generate different set of inputs and outputs for my bitcoins transactions.

My question is, does this really add up considerable (or any) protection or privacy to my bitcoins in theft/backtracking or any other kind of so far known attacks?

Thank you.
do you mean "anonymize" insteadt of "protect"? if so:

in general: no

everybody can track your bitcoin-transfers on the blockchain. so everybody can theoretically comprehend that you have used a mixer-service. if your mixer-service does really mix your bitcoin, you must still trust your mixer-service that it will never provide some information about that mixing-process in future to anybody. (but maybe this service will be hacked in future or the service must provide some information to a prosecuting authority for example.)

hint: you can improve your anonymity a little bit by changing your bitcoins to a cryotocurrency which has a little bit more anonymity/privacy (for example monero) and then make some transactions and change it back to bitcoin.