So you cede that these issues exist. Great.
Did my reply imply as much? I don't think they are issues - that's why I was asking. After bitserve, fluidjax too pointed out the meaninglessness of focusing on 51% attacks as segwit-specific attack vectors.
Fungibility isn't a real issue, either - still IMHO. As SW transactions become the majority, only old or newborn coins will be left in your Type 1 (coins that were never touched by a SW transaction). Besides, LN acts as a kind of giant mega-tumbler. If/when LN really gets into widespread use, it will only help fungibility rather than undermine it.
Geeze, JJG - you need to look up the definition of 'fungible'. Within the three posts preceding yours, 2/3 of them stated that they were cautious of accepting Segwit transactions until they gained some confidence in it. That is definitively a lack of fungibility. A lack of fungibility is in no way limited to some sort of centralized blacklisting.
Those two posters stated that they were wary of SW transactions right after the soft fork. This hasn't much to do with fungibility in my understanding - more of a reasonable wait-and-see attitude motivated by sane skepticism about the technology itself - skepticism that might have been triggered by the FUD wave that some were spreading at the time.
Peace out.
I'm totally cool.