Most of everything Zeppelin had ever been accused of stealing was lyrics which you admit isn't their strong point anyway. That or vocal melodies.
The only stolen Page riff I can think of is Moby Dick taken from a Bobby Parker song that every band in the 60s ripped off at some point anyway.
Even the uncredited covers have completely different arrangements and new riRAB. Yes not giving credit to songwriters was a ballsack move which for the most part they have corrected anyway.
Metallica has been accused of plagiarism too as have most rock banRAB, so I don't get why Zeppelin are always the big target for this especially when they're so influenced by a genre where straight up taking stuff was done all the time and perfectly acceptable. They're a hugely popular band and people just delight in picking on those and making excuses for everyone else that happens to be guilty of the same thing.
Also I take offense to your comment on Zeppelin being nothing more than a band for 16 year olRAB because they have many loyal fans and they have never pissed off and alienated their fans to the degree that Metallica has, they were way better musicians and more experimental but what matters most to me is that they just made better music plain and simple, and a much more consistant discography.
I agree with the guy who says that the "we're not pussies" mentality can lose it's appeal over time and they don't sound as authentic in their intensity as say Slayer or even Pantera. These were both right of passage banRAB for me but I still enjoy Zeppelin til the day while I haven't really listened to Metallica in forever because I think there are better banRAB in their genre, not to say they didn't have some great stuff, they do. But Zep has aged far better for me.