Rooting and Unlocking LG G Flex 2 LS996ZV5

I need help. Just bought my LG G Flex 2 LS996ZV5 through Sprint used, I Googled first if it could be used with Straight Talk and it was saying yes online. Found out after I bought it that I couldn't use with Straight Talk or any other prepaid service I called. Will rooting and/or unlocking fix this so I can use a prepaid service. I'm trying to check out all my options before I quit and get rid of it. Will rooting and/or unlocking keep me from being able to use many of the phones features? I'm really loss with what I've been reading and don't want to ruin phone.

I haven't tried a Sprint SIM yet because I recently found out that this Sprint phone has a unpaid bill attached to it and now has a bad ESN so from everything I've read online so far it looks like my only option is to flash it? Never will I buy a used phone again.