This line could be interpreted to mean two things:

The less likely case, that…

1) Cayea and his crew literally fuck everyone until their brains turn to mush.

… Or the more likely case, that…

2) Cayea and his crew not only rep themselves, but also everyone, in the hopes that the world learns and comprehends the velocity of the truths he and his crew are preaching.

Oxford Dictionary’s definition of spontaneous combustion:

Noun
the ignition of organic matter (e.g., hay or coal) without apparent cause, typically through heat generated internally by rapid oxidation.

Cayea’s saying his crew is so hot, they cause things and/or people to explode on the spot when they are in sight.

A reference to Thomas Jefferson’s famous quote:

https://twitter.com/tisnate_/statuses/211161353732362240

12 Reasons Honesty Is The Best Policy

http://www.youtube.com/watch?v=7rWtDMPaRD8

Central Intelligence is so hot, you’ll get burned just by listening to their verses. Storms solidifies the claim with a Pokémon reference to Charizard; in other words, the hottest in the game.

Storms claims it is not possible to comprehend how he acquired his said flossiness.

Taking a drink straight is preparing or ordering your liquor in a glass with nothing else in it. Ice is typically added to the drink, which would make it on the rocks.

But he’s also referring to his sense of fashion. He enjoys plain clothes without any flashy jewelry, unlike some rappers…

A play on the phrase to “pay attention.” The point that he’s been eluding to has finally been stated, which is that they’re donzo.

Sometimes the relationship seems to be working out, but he’s still hesitant to keep at it.