1 and 2 are fairly simple (I think), but 3 might be trickier since there isn't built in functionality for searching posts (though it wouldn't be hard to code the sql query yourself). Do you mean the same content shouldn't be posted by the same user more than 3 times in a row in a short time (also, what's your definition of "a short time"?), or the same content by any user?

1. you can't post more that 10 posts in 10 minutes
2. If you exceed the max posts 3 times in a day you'll be banned from posting for 2 days
3. To not let the same post be posted more than 3 times in a row in a short time

etc things like this... what do you think?

Currently there's no such component.
What's your idea of what criteria should be met to mark a post as spam?