No, you don't you can have youtube on the 3ds browser. At first It says it doesn't work, but go out and go back in and your video will load. [Age restricted videos don't play regardless if you sign in]
-Use embed code for the games
-Use ai vor your favicon
-Use Java or HTML to make a play button for your games
-Try to find embed code for fullscreen games
-Contact the content creator to use their game