Provide for his girl and kid, or to make a change in the world.

Write about what you know is the best advice in any literal field

A crab nigga is basically a pussy — they hide in shells. Possibly their sideways movement signifies a lack of progression, but again, possibly not. Nas is saying that when him and his homeboys begin to take over, the snitches amongst them will rat out any possible breaking of the law, and thus hinder them
Line is sampled in Nas' “On The Real”

“Crab nigga” could also be referring to the idea of crabs in a barrel, that people stuck in a difficult situation will pull others down with them and keep them from getting out. This makes sense in the next line, that when Nas and his friend get something going, others will just rat him out.

Clive was residing at Rikers Island jail complex, but due to the assault mentioned above, he has been moved to Elmira Correctional Facility, a maximum security prison. Nas is saying that there are some nasty dudes there, so Clive needs to keep his head down to avoid any horrific incidents

Note the juxtaposition of fire and showers (in the next line).

Nas again tells Clive to show some resolve, as when he’s out, he can run the ends with Nas

Some dudes tried some ‘funny business’ with Clive during shower time. Nas kindly enclosed a bottle of shower gel inside the parcel

Nas can stop bullshit like the above occurring

The dude Clive shot last year, which is presumably the act he is serving time for, has been trying to act cool in the ends where Clive used to rep. One of Clive’s old friends bought this pussy’s act, and now hangs out with him. Even worse, he gave this dude Clive’s gun! Ultimate deceit

Again, the incarceration of Clive leads to a betrayal on the home front. His baby’s mama is already shacked up with someone from a rival crew, and now it comes to light that his former running mate on the streets has teamed up with the dude that Clive shot—and he’s running around on Clive’s corner with Clive’s gun! Et tu, Brute?

Time has elapsed, Clive, (can we call him Clive this verse?) just needs to hang in there now. The use of “born” as a greeting suggests a tie to the Nation of Gods and Earths, as “born” is a part of their Supreme Alphabet

This is a similar concept to alligators, who before disposing of a victim, like to parade it around the area, often dragging it around from their jaws