I love the idea of alternating as well!

Now, you just have to decide what to alternate!! I think having each a little different, especially if you use different shades or colors, will look really classy and make each table unique - while still being a cohesive theme.
I don't think it looks too springy at all! My favorite is option 1 with the yellow and orange. Because it leaves turn that color before they turn red and fall off (which is kind of played up on the table). I like the idea of having something around the base as well, because it looks a little plain. But, if you don't like the leaves on the table, maybe a nice table runner or placemat under the centerpiece might give you the pop you're looking for. What color are your table linens? This is also a factor to consider when picking colors for the decorations...
I am going to have ivory skirts with burnt orange overlays. So maybe with the burnt orange in there it would make the flowers look more falley (i totally just made up that word, lol.
I totally agree! Maybe if you put the branches in the centerpiece and some leaves on the table you might get that "fallen leaf" look and be more "fall-y" how you wanted.
The only thing with the branches is then how would I use the candles? There is auctually a candle holder thing that sits in the cylinder. Or would I just break the branches to fit in the cylinder?
Also, have you thought of filling the cylinders with water and then putting whatever inside? That might be a cool idea ...

Something like this:
I can't see pictures at work but I tried water with the leaves and I HATED the way it looked. And besides I don't know if the reception site would be willing to do the set up if we used water.
They also make beads on garland that I bet you could find in your wedding colors -- like this:
I like these couple options as well:
Hope I'm not being too pushy - just my 2 cents!!
good luck!!