If your pet's health gets too low or its attacks aren't very effective against a certain combatant, you can always switch out your current pet with another companion on your team. Only pets that are considered active (i.e., those in your three Battle Pet Slots), may be switched in and out during the battle. Once the match is over, you can always change up your active pet team, which is useful if one of your pets is low on health or dead.
Within the context of Classic, the method most frequently proposed is to re-tune bosses to make them harder. Rather than copying the numbers, re-create the relative difficulty. Kind of like, when you first start working out, you use small weights. When you get stronger, you lift bigger weights. The WoW community is more knowledgeable, more experienced, has better hardware, etc. We're "stronger." So give us tougher bosses. There are a lot of forms that could take. Bosses were constantly re-tuned during vanilla anyway, so if Ragnaros does 10% more damage or something, is that really a problem? I don't think it is. What about resistance gear? back in the day, collecting resist gear was a thing people did. But the numbers and strategies are so well known today that only the tank really needs it anymore. Bosses could be re-tuned with more resistible elemental damage so that's important for entire raids to gear appropriately. That would be entirely keeping with the spirit of vanilla even if the actually numbers sitting in a database somewhere were different than they were ~13 years ago. If you want to go a little farther, a few people have proposed adding new abilities to old bosses, adjusting their timing, etc.
I received a beta invite for Classic, and had also been an alpha and beta tester for the original game 15 years ago. That isn't unique; plenty of people in Northshire Valley had had the same experience, suggesting to me that active players who were Day 1 WoW gamers or had participated in the original tests might have gotten priority invitations to this one.
So far i've done almost half in the past 2 weeks or so. I just want to know would it actually be beneficial to do the above tasks? Just all seems a bit too grindy, I feel like I've been wasting so much time doing old content that's not even needed any more... but I didn't mind doing them for the transmogs and such. I guess i'm just asking if this addon is really worth using and it's not suggesting unneeded filler.