As I said, angry as I am about it, I'm not going to hold it against the film til we know for sure.
Now as for your second point, you're absolutely right, and that stuff alone would be fine if this were some other franchise, that doesn't have the rich history of Star Wars. But it isn't some other franchise. And you can't introduce a character to a series like this, whose very existence poses so many questions, and then just kill him off without answering any of them.
If snoke really is dead, most people who are fans of the lore of star wars are going to see it as a missed opportunity, because there is so much they could have done.
If all he is, is a plot device, then I think that's really fucking lame.