Is there a difference between "In" and "Out" peer connections? On bitcoin-qt, some peers are called "Out" and some are "In". Is there any difference besides who initiated the connection?
No, connection directionality doesn't affect peer behavior in Bitcoin P2P at all. The same rules for relaying inventory, and punishments for misbehavior apply to both. The software will avoid making outgoing connections to peers in close proximity in the IP address space to one another, but this does not apply to incoming connections where many connections from even the same IP address are allowed.