I am having trouble with my wireless router when i play counter strike on my laptop which is wireless enabled there is an error mesage in the top right of the screen flush entity packets can some one help me plzzzzzzzzzzz
It probably needs some ports opened, or for a brute-force solution, place your laptop in the DMZ. Hardware firewalls are not really designed to work with online games.
If you can find out which ports CS uses (contact the server provider?) you can enter them into a new custom rule. In the config UI, go to Virtual Servers and select New Entry; CS may already be listed in the games section, but otherwise, select New User defined Service. Give it a name, select the types of port to open and enter the port number.
To the first question: um, probably! To the second question: Not sure, but it sounds like a choice between fixed and dynamic IP addresses depending on what your ISP gives you. You may not need the DMZ anyway, unless the firewall rule doesn't work.