You can buy 4 heroes with coins, so if you haven't filled up your slots yet, you can still change up, and the cards aren't wasted since you can move the best ones over to the new deck. I agree with you, though, it is terrible that you can't delete the hero like you can in every other game in the world.
Well, I decided to keep playing, got some pretty good cards, and started pillaging people. Then it froze while loading the next person to pillage, so I exited the app and tried to reopen it, and it won't get past the initial loading screen.
So I deleted it and re downloaded it again,and it still won't get past the initial loading screen, it just freezes there. It's a shame this app has so many problems, it seems like there was some potential here. Hopefully I'll be able to play again in a future patch.
"Even if a pawn becomes a queen, it's still just a playing piece." http://thankyouchrishansen.com/