I like the contests overall - maybe vary contests with expedition by giving points for earning expedition dollars and spending expedition dollars. Maybe up the points, but only slightly.
I wouldn't mind seeing a 'choose your own adventure' contest. When you log in, you tap contest, and it gives you 3 chests (or doorways) that has 1 of 3 contests with different heroes and different point options (for ex, door 1 has Roller Warrior, Bardbarian, and Snap Dragon with spending coliseum, expedition, and fight pit tokens; door 2 has Bone Dragon, Ninja Dwarf, and Crimson With, with spending coins, enery, and diamonds; door 3 uses 5 heroes, and spending and making coins).
Once you reached the first reward tier, you'd be given the next 3 doors with 3 new contests (or maybe an option to continue on the first path with 2 ne options). Contiue it up to the final tier.
This way, you can use the contest to work on characters you've fallen behind on, or perhaps release new characters.
As for the storyline, which I enjoy, perhaps new boards (not storyline boards, but contest maps that use the outrageous storyline changes) so that we can see things play out. Plus those boards could also be elite, and used to distribue new heroes soulcoins during the contest. If not new maps, maybe popups similar to the orange level challeneges when doing fight pit or coliseum battles.