It's probably your internet connections, I would get stuck at 43-44% because of slow internet! Now it's fast, And it has a low chance of stopping at 43-44%.
If you mean the 'Heroes' that do the the chatting or whatever's... You can't use sparks on Heroes, You can only use sparks to train creatures, And I have no other responses for your other problems, Except that they are probably bugs/glitches in ABC. PS: Breed higher ranking creatures to level up, And no, There are no…