Will I still be able to play TFC thru my router? Will I need to change some settings etc?

Play almost 100%

host a LAN game, maybe.

The routers are finicky things...

IF you run into any issues, the link sys router has a 'dmz' where you can take computers outside of the hardware firewall. You simply tell the router what IP to take outside and it removes you from the firewall protection, thusly allowing the games to work fine.

I remember each of us would sneak into the router and swap who was in the DMZ...

The only time this should be a problem is hosting games though... most firewalls only block inbound traffic...so playing games usually isnt a problem.

well, luckily, it all worked behind the router. Now, my voodoo 3 card is starting to crap out :(