when eko is talking to the drug dealers, they say "is it true what they say about you? that you have no soul"

It seems everyone on the island has some horrible secret, or we have been able to label them clearly as "good" or "bad" and the island has treated them thusly.

ive also read theories about lost souls on the island.

Any connection between eko's lost soul and what he faces on the island?

I personally think it's too early to tell. It's hard to tell what's what in the Lost Universe, especially with regards to one's soul. For all we know the Smoke could be some ancient soul eating demon that woke up when Dharma started digging. I did like the smoke's reaction to eko though. Seemed to judge him then move on, kinda like it gave him the benefit of the doubt.

May he is like an Angel character. Angel being the vampire trying to save the world so that he may regain his soul.

That was also the remark that made him mad enough to slit those guys' throats. Clearly a touchy subject, and after this episode, we can appreciate why.

I thought he was slitting their throats as if to say, "I'll prove it to ya, bitches"

It's clear that absolution is important to him. In what capacity and when this occurred to him, I don't think we know yet.

I did like the smoke's reaction to eko though. Seemed to judge him then move on, kinda like it gave him the benefit of the doubt.

Much like what happened to Locke during his first encounter ("looking into the eye of the island"). Later, however, he was being dragged into a hole by the "monster." I believe Smokey scans people and stores their memories, for whatever reason. Will Eko have another encounter with Smokey that may have very different results? Or, as a friend thinks, are there TWO "monsters" - one that sounds mechanical, and Smokey, which seems to have a "cricket" sound - that are roaming the island?