In accordance with the song, the backpack most likely has this guy.

The 816 Boys are a Strange Music joke. The don’t make “hood rap”, but this is their group to compose and perform their version of hood/gangbang rap. Tech N9ne, Krizz Kaliko, Kutt Kalhoun, and Makzilla are the current members of the 816 Boyz

Yelawolf is from Alabama, hes a country boy. The country has a totally different culture than the city and it is not unlikely to see this..

Pardon my French is a common excuse for excuse for using bad language. He is also being ignorant saying he’s got money so pardon his nice car too.

She has been drinking a lot of Pinot Noir, a french wine made from black grapes

DMX refers to himself as the dog, DMX stands for both Dark Man X and Dog Man X based on his love for dogs

Corpses in a morgue have tags on their toes to identify the patient so they can be pulled out when it is time for an autopsy

She won’t sign to a label that will talk her up like Def Jam did and not promote her; this also happened to the hip hop artist Hopsin at Ruthless where Tamika Wrigt played him but never promoted his albums.

She raps in this song so she is using slang like homegirl. She is saying people used to say she couldn’t “catch” attention when her music drops. Catching is commonly used in the music industry as a term to get a fanbase for example:
Tech N9ne

Lady Gaga was originally signed by def jam but was dropped so she was saying she was losing hearing to the music working her ass off