Well said Behoove. And I agree with you on the first three artists (?) you mentioned, I am not familiar with the rest and I don't think I want to be either.

If you want to make a name for yourself, you either have to be mad talented on the current genre or do something different. Singing about bling blings, hoes, cadillacs has been done by almost everybody else; why would people remember/appreciate you for that? Is your rythm/hook that much better (this is never the case)?
That was my suggestion to Boston boy, be a little different.
Maybe Royals by Lorde will inspire them a bit?

The kids in these rap-battle definitively have some talent and they present it in their own unique way. Hip-Hop/Rap do not need to be mindless banters; lyrics can be very powerful so put some thought to it. That's the way to go.