As far as I know, it is impossible to recover data on the 3DS if it has been deleted.
If you mean games you have downloaded from the eShop, then go onto the eShop and redownload it (subject to availability).
Access the 3DS eStore through the icon on the main menu. From here you can add funds to your wallet, purchase games, and download them. You can also redownload games you own but have deleted.
No - system restore is designed to 'roll back' your computer to a point in time before a problem occurred. It will undo installations, but not restore deleted files.
make folder name games and it will back again
You buy ds or 3ds games and then put them in your 3ds.
All 3DS applications and games downloaded from the Nintendo eShop can be deleted from the Data Management section of system settings: From the Data Management menu, select Nintendo 3DS, then software. Select the application you want to remove, select "Delete" and confirm.
by restore.
No, 3DS games can only be played on the 3DS.
The deleted files are from the MicroSD card, not the R4. You can use some Data Recovery programs, which might be able to recover whatever you deleted, but you are better off copying the files from your computer again (if you have a backup, or can redownload it)
no
You can restore a bookmark only if you have Time Capsule installed.
Yes, it does. There are Nintendo 3DS games that are exclusively for the 3DS family.
to restore a deleted recycle bin, one would have to follow these directions, open the recycle bin icon on the desktop, right click on the selection and then hit restore