So this is the set of 10 you got, right Jesse?

Exactly.
What's the deal with the "description papers"? That guy's site says you can get all 10 different papers for an extra $2.50. Are there really 10 different ones? What'd you get? Did they come packaged in any way? Individually, or as a set? Can't recall...
Like shown in the link Dale posted (thanks by the way

), all of the description papers are the same on one side, and then on the other side have individual descriptions for each figure they came with. I only received one paper (Darth Laser), but since all of the writing is in German anyway I wasn't too worried about getting them all.
Also, is this landspeeder the same scale as these figures?

I can't remember where I read it, possibly in the Rebelscum section on these Hippos, but I believe the landspeeder is the same scale as the figures.
And lastly, can someone remind me WHY I "need" these again? 
Because they're so damn cute! Come on, they've got chick magnet written all over them. What woman could resist a man who has a miniature hippo who's posed like Yoda. I mean really, what kind of question is that?

But seriously (sort of), I think they're cute, and like you said earlier, they are a finite collection that takes up very little space. I really have no plans to collect the rest of the various items, although like Dale said, that diorama is pretty sweet.