One thing I'd like to point out is that many of the pro-Kyle group are talking about Rosenbaum's alleged death threat as if it were proven. It is not. We only have the word of Rittenhouse and one of the guys marching with him that this actually happened.
What we do know is that Rittenhouse was aware that Rosenbaum was unarmed. (We know this because KR admitted it under questioning) Bearing that in mind, I'd say that the supposed death threat is irrelevant in deciding whether he's guilty, both because it's merely an allegation without audio evidence and (more importantly, IMO) the fact that Rittenhouse, being armed with a firearm, should have no reason to fear a man who he knew was unarmed, despite any threats he may or may not have made.
It's within the realm of possibility that Rittenhouse feared that Rosenbaum would disarm him and use the gun against him, but anything allegedly stated by Rosenbaum earlier, makes zero difference to that scenario....