Yes, connections to a peer is limited to 3. This limit was put to reduce amount of BitTorrent protocol specific information compared to the user data that is transfered. Data is transfered faster than having open 5 connections to the peer. Of course we are talking significantly less than 1% advantage here, but still we want to be the fastest way. By creating 5-10-50 connections, your data won't transfer faster. You will reach the limit of your network with 3 connections.