The AirPort Express is quite easy to set up. I strongly suggest you use the parameters I have posted above.
I really don't see the point your screen shots....
It sets your DNS to use Google, the 8.8.8.8. Sets your domain name to "Google.com" and then sets the unit to bridge mode, which disables NAT.
The second one really just forces your Channel to 1, instead of allowing the Airport to decide which channel it best "Auto" (which is does a great job of.) It also sets it to be 802.11n protocol in 802.11b/g mode, which is fine (but I think that is the default mode.)
So my airport setting for Disney are:
[Airport -> Wireless]
Wireless Mode: Create Wireless Network
Network Name: Aurora
Channel: Automatic
Security: WPA2 Personal
Password: is umm Set
[Internet -> Internet Connection]
Connect Using: Ethernet
Configure IPV4 Using DHCP
Connection Sharing: Share a public IP Address (this means you have to dismiss a "Double NAT" error)
[Internet -> DHCP]
DHCP Beginning Address 172.16.0.2
Ending Address: 172.16.0.200
[Internet -> NAT]
Enable NAT Port Mapping Protocol: checked