okay I'll try to walk through this. you posted something from David Shuster that claimed the cops and interviews with the family that the shooter was far right of Kirk. notice he mentions no source for this; provides no link and there is no reporting out there apart from him that this is true.
your Groyper theory is grounded in this
"
A Facebook photo in which Robinson
appears to reference a Groyper meme has led to early speculation that Kirk’s killing may have been an outgrowth of these intra-far-right skirmishes. "
Even the article you posted says this is inconclusive.
meanwhile reporting has come out that people that knew him said he had shifted left and became increasingly political (to the left) - I posted an article from the Guardian (hardly a right wing rag) with such information.
you are being duped.