use an emitter
You cannot.
you cant
With a scoreboard
Make a really good level
Make a good level
Make a good level
Use options to make it a favorite
Because you can make your own levels
You just go to create mode and make anything
Hard question, but in my opinion, yes. In ModnationRacers you can make better mods and tracks + it's easier to make karts. But in LittleBigPlanet, you can create whole levels instead of tracks.
Just make a good level.
Depends on how many PSN accounts you have