It would also explain why he was able to feel his fellow stormtrooper die during the opening scene and why he last more than 5 seconds vs Kylo Ren at the end. Maybe slightly Force sensitive?
I never really knew if Finn was Force sensitive or not; I thought Abrams may have just left it up in the air. However, I do recall that I thought it was apparent in the opening scene of the movie. But after hearing others thoughts, I had my doubts.
Now in retrospect, here's my list of reasons Finn is almost certainly a Force sensitive:
1) He feels his friend die.
2) He rejects the programming / brainwashing of the Empire.
3) Kylo Ren almost assuredly senses something with Finn; and I think this would be very unlikely if Finn wasn't Force sensitive.
4) Ren wants Phasma to look into it.
5) Finn wields a lightsaber without killing himself.
6) Finn shows incredible "luck" in a universe where luck
is the Force.
7) Finn's "chance" meeting with Poe and Rey.
8) Finn, in this scene, clearly hears the million cries, etc, before the people even die.
9) Finn clearly knows what happens in the Hosnian system even though no one else did.
10) Maz Kanata gives Finn a lightsaber and tells him to use it; given what we know of her, this is not simply by chance or coincidence -- she's telling him to start down a particular path.
11) At this point, it becomes fairly obvious, Finn wants to be a Jedi (see: Luke).
12) Finn seems pure of heart, even when everyone else around him is not (see: Luke).
13) Finn lands a blow on Kylo Ren during their dual; should be next to impossible for a non-Force user.
I mean... This scene was pretty obvious but I apparently missed it so I'm sure there's even more stuff.
So if we're weighing the options here; I'm not sure why one would assume he isn't Force sensitive? Or would be in anyway only marginally sensitive. It seems interesting though.. But if I had to guess, I'd think both Rey and Finn will be the beginning of a new Jedi Order.
From a purely practical standpoint; I also highly doubt they'll take Finn off of being a lightsaber user considering how much the actor enjoyed the part... Obviously he doesn't have Luke's lightsaber any longer, but, considering he'll meet up with Rey likely in the first act of the next movie, it shouldn't take him very long to get/build another one --
or to get one from Leia (much more likely?).