Gold’s threat was very real, he meant what he said. Of course he made the threat out of the mood of the current situation with Belle, so somewhat hot-headed, but I am sure, that if any (more) harm would happen to Belle, we would see a furious Gold, lashing out at anyone he helds responsible. Rumple likes to blame others, as he blamed the Blue Fairy for his failure to trust his son and go with him, and likes to shift responsibilities on to others, manipulating them into doing things for his own merit, taking advantage of their wishes and fears, pretending he leaves them any real choices. That was a real threat he made, and I hope it will come back to haunt him. It should.
I agree. I understand why he did what he did, but putting the whole responsibility on the Charming Family is just a way for him to have someone to blame other than himself.
I also don’t think he would kill Emma. So far, she hasn’t done anything but help him really. She has actually been pretty much maintaining some level of peace in the town. At least until Cora decides to change that, and judging from the spoilers, she will. Nor would she kill him–she may not like him or trust him, but it doesn’t give her motive. Even with the threat, I think she will be on her guard–she may feel a bit of sympathy for him, seeing him struggle outside Stroybrooke and all, but I doubt they will be fast friends.
I have a feeling that Emma may not be that easy to kill, even for Rumpelstiltskin. Cora (who is probably almost on par with her former teacher) could not even rip her heart out.