No problem Spooky,
You're absolutely right about this site... I feel the same way. There just aren't enough people around me in my everyday life that could stand listening to me talk about Halloween so much.

More ideas:

When I think of haunted carnival, I usually go straight to the old time carnivals that traveled by trains, stopping at towns along the way. I was trying to think of an idea to incorporate that and it really depends on the area you are working with, but the idea is:
To make a mock train car -- hear me out now, it really doesn't have to be expensive or in depth...

Look at this picture first... that middle car...


Just the facade - you've got the top section, some bars, and a bottom... that's it -- that's a matter of some plywood and PVC pipe. I picture it outside in your backyard, recessed a bit into the bushes or something (obviously on a bit larger scale than that picture). Cut out the plywood, paint it all up however you'd like... PVC pipe for bars, but have a handfull of the pipe in the middle be broken, bent, and ripped open like an animal escaped.

If you want to go further, you could create another car, similar, and have the "cage" broken a bit with a person inside, torn up. Imagine the tiger and lion got a hold of the trainer or broke loose... It looks great in my head

For more ambiance:
Space fillers for rooms and empty/blank corners = wooden crates labeled with carnival supplies (maybe 2 or 3 crates stacked up with worn, old text on it for "Roller Coaster Parts," "Tent Repair," "Trapeze Netting," etc, etc).

I'm trying to think of everything that could be a part of a traveling carnival. Have you ever read Something Wicked This Way Comes by Ray Bradbury? Novel from the 60's about an evil traveling carnival that comes to a Midwest town. (Disney made it into a movie as well). Anyway, that's what I think of with your theme, but I usually go for the classic stuff in my themes - I love the older, less obvious adaptations to Halloween themes (example: if someone were to say, lets do a theme about movie characters, I'd immediately want to do it about old, classic characters, instead of modern movie characters). So that's the way I lean towards... just to give you a better idea.

Ok, back to ideas - sorry for the tangent.

For your front door (or whatever door guest come into) I was thinking of a facade similar to a trailer at a carnival. Lets say a carnival is set up and they have trailers for the workers to live in. One of the trailers is for the bearded lady, another for the trapeze artist, etc... you could craft a large 'sign' (carved similar to the top of one of those train cars) and hand above the door -- or even better maybe -- in each room or entry way, have one of those hang above with different text (Freak Show, Animals, etc) and on the front entry way have a large sign above saying something like "Main Circus Tent" or something.