Linksys does support the ability to not broadcast the SSID, and thats a definite in something to do. WEP is a definite as well.

I personally do not feel its necessary to have a personal firewall on a machine that is already behind a NAT router, but to each there own. THe only reason I would use a firewall type program when I am behind NAT, is for detecing virii or trojans that you get through mail from getting out to the internet.