I also fail to see Scapegoat's usefulness in the deck. Against mass removal Wrap in Vigor does the job (Perish, WoG, aside) in protecting the horde - but noone plays that card either. I don't see the added benefit of replaying all your elves as it becomes overkill. Two ways to go with this deck are such:
1. Storm via Grapeshot/Tendrils/etc
2. Elf-ball into Emrakul
Bouncing all your guys as a defensive measure seems good on paper, until you realize that reset the board state won't always help you recover in time, and essentially not against Counterbalance. On the offensive, its just plain Win More.
You mentioned that with Kobolds it's a great card. I agree for this purpose. Elves aren't as explosive as Kobolds with retriggers on Glimpse, even when Elves effectively cost 0 or negative mana, and much more interaction based than simply casting a Kobold. (tap 3 elves, untap X Nettle Sentinels, draw a card for each elf cast - this can get tedious after several rounds)
Wirewood Symbiote works well enough in bouncing Quirion Rangers. At that point, you should have more than enough mana and Glimpse triggers to sustain the combo through the end. Symbiote also is a lightning rod that protects against spot removal (both in countering the removal, and by eating the removal himself).
RE: Crop Rotation and Gaea's Cradle
This has been mentioned over and over. It's a preference call, but it appears most of the people in this thread prefer a rock solid mana base (basic Forests, fetchland) to the chance of opening up a must-mulligan hand contaning 1 or more Gaea's Cradle. The risks outweigh the benefits of the extra mana boost.