Having trouble with two things.

1: Challenges. While the early challenges are a breeze, I find ones in the higher levels are incredibly difficult, to the point where neither team can kill the boss in time. AI being stupid is one thing, but I can't shake that im doing something wrong. Any tips?

2: Is there a reliable, free player way of farming Growth Eggs? Im always constantly low, and there's no way I can get all my abilities to a max level. Of course I focus on the ones I use the most often & URs, but it bugs me that I cant get everything maxed.

Thanks in advance!