If i am fusing 2 uncommon pets (max level 50), do both skills need to be 50 in order to have max level 70 on my rare? or do both need to just have the primary skill maxed at 50?

Just the first ability on both pets needs to be maxed to 50 to unlock lvl 70. The 2nd ability on both pets does not need to be maxed. I however believe it is better to fully max both pets to 50/50 because it's only 30 fame per feed. Rare is 100 fame per feed. It's completely up to you though.