This is a reference to people who act tough and project a gangster persona, but when they come across real gangsters they get exposed as soft, timid and scared – like a rabbit.

This is underscored by the following two lines – posers get killed, so don’t act tough if you can’t back it up.

Abel shows regret for his decision to be famous and tells this opportunistic girl that if he had the chance to do it all over again, he would’ve never agreed to letting her into his life.

This also refers to the music business. If he had known that the record labels would have become so obsessed with him, he would have left the music in the club instead of letting it be such a major part in his life and be the path for his fame and success.

The Weeknd’s discography, in its simplest form, is a recital of events which make it quite clear to the world what he is after – uncommitted, high sex.
Nothing more and certainly not love, or to be tied down permanently with one lady.
He states things such as…

Baby I’m a pro at letting go, I love it when they come and go - Montreal

But, as previously stated, in ‘Echoes of Silence’ with the lines

Cause you thought there was more to us but you knew how this would end. It’s gonna end how you expected girl you’re such a masochist and I ask why

These women tend to ignore/forget this, falsely believing they will not be disposable, and will be the first to tame him or tie him down.
But they all fail; he is a nomad.