no.
computer
There are a number of places where a person can buy an assortment of Nintendo DSI accessories. These include Amazon and eBay.
GameStop, Amazon, eBay
amazon UK
over the amazon,nitendo or ebay i think.
If you buy the game in the shops, no. You cannot save your image on to your computer. But, if you buy the game online on the DSi Shop built into your DSi, you can save your images to the SD card and post them to Facebook.
yes it can just buy the card of amazon or eBay but amazons better Yes it does. You can buy the card at amazon, eBay etc. It's your decision.
Only if your computer has a wired connection instead of wireless. If you are using wireless, the DSi can connect to your router, it has its own wireless capabilities inside it. If you are not using wireless, you can buy a Nintendo USB wi-fi adaptor which plugs into your computer and turns it into a wireless hotspot that the DSi can connect to.
That's not how the DSi works - for one, code can't be executed from the SD card anyway. What you need to do is connect the DSi to the DSi store, and download the games there after you buy them.
GameStop, Amazon, any place that sells video game accesories.
not necessarily. if you have wireless Internet use that, or hook it up to your computer.
You can buy games from the built-in DSi Shop using Nintendo Points. You need a compatible Wi-Fi Network, though.