We don't need no Steenkin FirewallFollow

I have a wireless netweork with an ADSL modem/router and I am trying to set up my firewall so I can play DAOC. I found the following from Mythic:

All UDP ports 1024->65535
TCP ports 1280, 10500 and 10622

If i have to open ALL UDP Ports from 1024->65535, that sort of defeats the object of having a firewall.

Is there a subset of ports which I can open or do I really need to open them all?

Have other people with firewalls opened this port range and not suffered major virus probles