No. 3DS game cards have a small tab on the side, so they don't fit into the Nintendo DS or the Nintendo DSi. Even without the tab, 3DS game cards will have much more data and better graphics on them than DS cards. The technology is too advanced for the Nintendo DS and DSi so the other DS systems would not be able to run them.
Yes you can, the two consoles can communicate with each other just fine.
no
can you oovoo on nintendo 3ds
platinum get arceus this year from a Nintendo event, get someone to trade you one from a platinum game
yes you purchase them using Nintendo points you have to buy Nintendo points at the Nintendo website
yes
You will have to reset your DS or what ever Nintendo system your using.
Yes, it's a Nintendo game produced by Nintendo, using characters licensed from Sega.
No.
Using the Nintendo eShop.
No, A Nintendo DS is not compatible with a PC controller.
if he smacks it over your head, yes.
You can protect yourself against identity theft and fraud by using services such as Lifelock. You can learn more about this service at the official Lifelock website.
Magic is most often used against bad things, the devil is a Christian entity, if someone using magic see's the devil as something that they need protection against then yes, magic can be used.