Playing specific card keywords is not fun. Just put all enrage cards into a deck and play casual. I get it for new players its a thing to inspire new types of decks....but the cards aren't there! If there were good cards of each keyword, then maybe the quests would encourage diversity in decks. Right now they just encourage brain dead auto fill decks.
I like some of the keyword ones, like 'beast' or 'divine shield'. I made a new paladin deck which focussed a little more on divine shield and it works pretty well. But I don't want to play an 'enrage' deck. It might help if we could switch out more than one quest per day.
The "Battlecry" keyword is okay to satisfy if you can make a dragon deck. "Deathrattle" keyword can be hit reasonably with Hunter. "Divine Shield" is meh but okay to satisfy with Paladin if you use Argent Squire, Argent Horserider, and Shielded Minibot if in Wild.
Why do they make you play 30 murlocs but only 10 pirates? Both murloc decks and pirate decks run out of steam at around the same point. Murloc swarm a bit, but not from hand. This is not even getting into the 75 Murloc quest.
"Enrage" quest is dumb with so few strong Enrage minions, but Amani Berserker, Bloodhoof Brave, and Aberrant Berserker will get you there with only 10 Enrage cards needed to play.
"Inspire" quest where you must hero power 30 times for 50 gold? That's gotta be the worst quest right now.
Edit: I do feel like these quests are annoying for someone playing as long as I have overall, but more frustrating is that these quests were introduced with absolutely no warning to allow for collective player feedback beforehand.