Epilepsy is a disorder which causes shaking and seizures. An Etch-A Sketch is a child’s toy in which you control two dials to create a picture, then shake it to erase the image.
Asking how you “shake ‘em” is another way of saying “how you relax” or “how you kick it”. Shad finishes the thought by talking about the rough scenes that you may go through (Etch-A Sketch scenes), but you must force yourself to erase them and move on.

This could also be a subtle jab at rapper 2 Chainz, who is known for his materialistic lyrics which Lecrae doesn’t agree with. Last year, under his new moniker 2 Chainz, he released a mixtape entitled T.R.U. Realigion, where he is wearing all denim. This could in fact be a triple entendre.
Someone out their is idolizing these rappers, wishing they can move from their poor, impoverished life into the life of luxury that is associated with rappers.
Also, the beat of this song is Rick Ross' “Tears of Joy” off his Teflon Don album.
“In that SL” refers to the Mercedes SL, a high end coupe.
Getting deeper in the subject of race, Ghost is saying black people don’t understand what they’re doing and make bad choices; eating fried chicken and abusing over-the-counter drugs.
A play of words, referencing Sir Mix-A-Lot’s Put Em On The Glass while talking about a girl getting wild when drugs and alcohol are mixed.
Also, cadence is another word for “flow”. Nickel it thanking God for gifting him with his flow.
Jakk Frost is also a rapper who was known to body beats, Royce respects.
Also, in this interview, DOOM states that when he’s rhyming in his King Geedorah moniker, he tends to rhyme things that have to do with 3s, the same amount of heads that the original godzilla villain of the same name has.
No, if anything, he’s punning Curtis “50 Cent” Jackson’s name, who Wu'Tang had a beef with around this time (mostly GZA). He’s associating 50’s name with the cops.