A simple theory on the loophole and it's exploitation by MrHootless

I realise that now we are in season six that a theory on the above topic might be a bit outdated, but here goes:

I have a theory about the loophole and its final exploitaion. I haven't read every theory posted here so if someone else has already posted the theory below, apologies!

The smoke monster could only kill Jacob (and perhaps can only kill other people) when it isn't in human form.

When we first see the MIB, he walks onto the beach to find Jacob and they have their polite conversation, during which of course the MIB expresses his desire to kill Jacob.

As of yet, we have never seen the smoke monster in its non-human form on the beach/coast. I have no idea as to why this might be, but in the first season just after flight 815 crashes, the smoke monster is uprooting trees and making a lot of noise. Could it be frustration at not being able to get to the losties?

At some point in the 70s after Horace Goodspeed has built the cabin Jacob took residence in it. I am assuming at this point that Horace and family were no longer using it otherwise it would have lead to an awkward situation no doubt. Some time later he abandoned it (We don't know why he moved there in the first place or why he vacated it).

While Jacob was resident in the cabin he needed the circle of ash to protect him from the smoke monster since this was the smoke monster's territory. I don't know at this stage whether the MIB would be able to cross the circle of ash - as yet there isn't any information to suggest otherwise.

As long as Jacob was on the beach (and there were no humans around who could be manipulated by the MIB/Smokie) Jacob was perfectly safe. The loophole was exploited when MIB presented himself as "Locke the leader" and was able to bring someone else along with him who was ready and willing to kill Jacob.

When Bram fired a shot at Flocke in the base of the statue, the bullet effectively bounced off Flocke having no effect. Flocke then changed into the monster, killed his attackers (to be fair, he gave them the opportunity to retreat first) and then turns back into Flocke again - is this coincidence?

I am certain that Flocke doesn't have the power to kill anyone, but can only arrange their death through manipulating another.

Of course any counter-examples or intelligent debate as well as further insight is appreciated.