The "stars" are your "battle ranking" in the multi-player games on Main Street.
Yes you can get 5 stars.
Work hard.
You try beating people with more stars in multiplayer games.
nothing
It means you were hit by something.
follow the footprints from one of the stars
you have to go to the common room and click on a person and battle him. by battling the person you will earn stars. keep battling him to get 5 stars.
Throw the star
You aim with the mouse and press the space bar to shoot.
In the Main Street multi-player games, beat someone with more stars than you to advance your own rating.
Beat someone with a higher star ranking than you
You throw one of your stars to cut the rope holding Jack and Annie's cell to the roof.