I'm going to keep this brief (as ever) but if you need to talk about anything more, AIM is the way to go!
Violet and Sam probably don't know him, so I'll get those two out the way first! Both would be civil if they were to meet though!
Toby is in his house, but the year below. He probably knows Eddie in passing.
Gwen and Oliver would both know him from class. Both would probably get along with him casually, Gwen probably more so. Friends all around?
Aaaaaaand Casey! He's a roommate of Eddie's and I think they'd get along great! Casey is naff with girls, so might appreciate Eddie's help? The boy is off his rocker about Quidditch (in case that wasn't obvious), so as long as Eddie is equip to deal with that, I see no problems! Close mates, for sure!