There a list of ports that need to be open or some other limitation on patching I find it incredibly slow.

Have a 300mbps internet connection and I am sharing out at 45mbps but the download for this game is under 200kbps.

I assume it is using Peer to Peer and I may need to open up ports in a firewall?

Or is there something else I should look at?

you should look at how many people are downloading the update files, when there's a high demand of download over the server the speed goes down for everyone