1) You will need to setup an initscript to do those commands for you, there are lots of tutorials out on google that will help you.
But I wouldn't use iwlist wlan0 scanning to setup the correct parameters for your card. If you want a specific AP, you want to do
iwconfig wlan0 essid "myap"
or if you want it to autochoose one, then do iwconfig wlan0 essid ""
2) You need to follow the conventions for the fstab file, it is not read like a normal script file.
/dev/hda5 /mnt/windows/ ntfs ro 0 0
but you need tabs instead of spaces in between them. Just follow the form of the other entries to get it right.