@Bored...
You should at least configure your firewall to open port 6346 (or whatever port you are using for LimeWire) for incoming TCP and UDP traffic.

@Cougar
I don't think the number of leafs per ultrapeer will be increased. It's not so much the traffic that you couldn't handle, ultrapeers handling too many leafs cause problems with intra-ultrapeer query-routing: other ultrapeers will send you too many queries that do not match any of the files you or your leafs are sharing, increasing traffic for all ultrapeers connected to you.