Well yes, but my point is that there's GPP that will help a given task and then there's GPP that, while it may indeed (for example) help your health, may or may not be beneficial for what you are training for. Again, a continuum of usefulness, the distinction between GPP and SPP is made in the context of a goal.
We could argue this for the sake of arguing, I guess, but if I was confronted with a gamer that wanted to improve his gaming (and presumably general health), then improving his squat 1rm would be really really low on the list of priorities UNLESS they were already so weak that getting out of a chair was a struggle.
Well, if we're using GPP interchangeably with "general strength/fitness/health", then yes. Again, I distinguish GPP as something at the top of an inverted pyramid with SPP at the point with a goal underlying the pyramid itself.
Yes, I think anyone here would be in complete agreement that KB work is good GPP for PL. Absolutely.