So two points:
1. While the idea of whether Finn is Force sensitive or not is a developing one, one way or the other, it is CLEAR that he is operating under the will of The Force. If Finn doesn’t have his miraculous break from his training and indoctrination AT THE PRECISE MOMENT THAT HE DOES, Poe does not escape from the First Order, Rey does not appreciate the urgency of getting BB-8 to the Resistance, Han Solo doesn’t get back the Falcon, the strategic plan that destroys Star Killer is not formulated, and none of the Han/Ben dynamic ever takes place (which I believe will be the centerpiece for VIII and IX) at least in the timeline set forth in TFA. So FINN’s presence in TFA is as absolutely critical to the story as any other character in TFA.
I continue to be surprised that people are still reporting that they are not drawn to this wide-eyed, accessible, funny, brave and heroic character. I think he and Rey together carry the Luke Skywalker mantel for the Sequel Trilogy. So if you’re “not getting” Finn, or are refusing to because he doesn’t fit your personal template of a Star Wars hero, you may also not be getting the entire ST because I think he is/will be at its heart.
2. The attraction of Finn to Rey is obvious. Through the movie, the bond evolves and branches out into new levels and intensities, but, for Finn at least, the core of their relationship is that he is beginning to love her, and he’s hoping for signs of reciprocation (I know I’ve never been in this situation, but perhaps some of you guys can relate
). This is also another huge reason why I’m drawn very personally to Finn’s character. Who hasn’t been here (besides me, of course)? Identifying with his yearning to have his feelings returned is a big factor for me. It certainly looked as though Rey was in the process of Friend Zoning Finn at the end of the movie, so maybe she will make that official at some point in VII, but I don’t think its possible to deny the dynamic that’s there on the screen between the two.
I fear that some may just not like the "look” of them together, and that scares and repulses me at the same time…