I'm also hosting a F.E.A.R. server from home and don't have any problems with lag, but I got a 20Mbit connection at home, limited to 41Gb download and 13Gb upload with a static ip.
The only bottleneck I have is with my cpu, which tends to go higher in usage when server is completely full with players, then it's constantly @ 80%, simply because I'm also playing the game myself on the same machine.
Best thing is to host the game on a different machine, as said before and make sure you have a fast network and some decent hardware.
grtz
-B.O.W.-@nimine