Yes, however, your internet speed will only be that of the G router which is comparably slower than that of an N router.
The Linksys Dual-band Wireless A+g Notebook/laptop Router is good.
Yes.
You can use router of G or N type and the same type wireless adapter. Of course you can use wireless N adapter with G-type router and reverse.
Any laptop manufactured during the past five to ten years will have an 802.11 b, g, or n wireless interface. Any standard 802.11 b/g/n wireless router will work with any b/g/n laptop, but you may wish to use your computer's Device Manager to see which type your laptop has since you may not want to buy a more expensive 802.11n router if your laptop can only use 802.11b speeds.
802.11
Yes.
A Wireless G router provides Wireless access to 802.11g compatible devices
The same as with wireless G card and G router.
yes it can
There is no significant advantage, you would need a wireless networking card on the expresscard slot, usb port, or on the internal mini-pci express slots.
No.
Usually they are, you have configure the router for G wireless networks.