It does serve this purpose for sure. Though I think that we could assume Han would see through Finn’s act regardless, and I kind of like that Han might go on nothing more than his instinct rather than on a cartoonish incompetence that is IMO too much a part of Finn’s characterization.

As for Rey simply appearing in scene, I agree that it’s still too abrupt, and actually made a version 3 the other day before calling it quits:

https://vimeo.com/296396694
Password: Fanedit

Rey now appears briefly entering the room. Added footsteps would be a good idea.

I had shown the previous versions to my brother, who doesn’t care for this movie anyway, and he pointed out that the movie feels cut to pieces in this scene even before any edit, so I tried to consolidate and lengthen shots to give it more substance. That is why Finn’s reaction shot is absent, with Han’s shots on either side stitched together. I tend to agree with you that this reaction shot is necessary however, so the deletion will probably remain just a proof of concept.