I was lucky enough to be front row in Virginia early 80's and again 2 shows in a row in Detroit wit Hagar ...All the tunes were note for note clean and true to the records/tapes RIP Eddie. :-(
Doubtful the Cancer was from metal picks, he used plactic VH labeled picks and tossed them out constantly at shows. He also always had a smoke stuck between, on and under the strings. you can see the burns all over the FrankenStrat.