Valdez is not particularly famous for shore fishing, although there are a few areas that turn up in various fishing boards. I believe you'll be there before the Silvers really turn up, so that would leave Pink and Dog (Chum) salmon as the principal species. Pinks can be impressive when they mass at creek mouths, but generally are only catchable by snagging, which I personally don't enjoy much. Not very good eating, either. Probably I'd be looking for some stream fishing for Dolly Varden instead.

I can't answer this as I've only been to Barrow on business and never bothered with the tourist stuff. $60 doesn't seem like a lot of money to get to the tip of the continent, compared to some other things you're doing. You might also get to chat with some local native people one-on-one during the drive, which might be interesting.

Same "worth it" question. "Worth it" compared to what?

Given you'll have already seen a lot of tidewater glaciers, if it was me, I'd take the $123 and pay for the car's passage on the state ferry from Valdez to Whittier, and scrub a really long drive back to Anchorage. The ferry is smooth and scenic, and just as fast if not faster than the drive. You could catch Byron/Portage Glacier etc. on the way out of the tunnel if you wanted.

Speaking of accessible glaciers, were you planning to stop at the Matanuska Glacier alongside the Glenn Highway?