Leo is a senior! He is only occasionally good at friendly people. He IS good at book learning. He would absolutely seize up at personal questions, which means Mercy should have probably had the opportunity to ask them at some point because that's funny.
Addy is an Azurcrest and she looks up to and loves the seniors with all her heart. They should please be friends. Addy would take her morbid side completely in stride, because ~a person isn't just one thing~, after all. She would also think her senior project is AMAZING, which it is.
Ferdie probably has very little overlap, thinks she is just friendly, it's fine.