You could have damaged your digitiser cable during the repair. The digitiser cables are extremely fragile, and if they are damaged the your phone will not respond to touch. Try either using your screen on another 3GS, or a different screen on your 3GS.
Also-
No 6 Connector is Wifi Antenna
No 7 is Wireless signal antenna
Neither of these should cause the touch screen to be unresponsive, just bad wifi and GSM connection.
Last thing to check, is that the phone has started up properly before you try an use the touch screen. My 3GS takes 30 secs - 1 min after booting before the phone has started up properly, and the touch screen works.
Hope this helps.
Michael