What are the bad thing of iphone with bad esn?

I recently bought an iphone 4 with bad esn and i'm not the original owner of the phone so I want to know if an iphone can be updated to the latest ios even thou it has a bad esn? And also will connecting it to itunes lock the phone on anyway and how can i prevent the iphone to have a icloud lock or anything like that? I really want to use the phone as an ipod touch but i'm afraid that one day or anything that i do will lock the phone and prevent me from using it

also i wanted to know if i can jailbreak the phone with bad esn?

The bad thing of a bad ESN is that it means the phone is stolen. There's no way to get it to work, and it can be traced whenever you turn it on. Return the stolen phone to the police and pay for your own phone.