I'd have to do some testing to really say for sure, about how many ranks are needed. My comment about only needing a rank or two, is because I don't think that in MOST cases, you would need all 3 ranks. How many critters are you actually hunting that you need a 3 foot higher reach?
Even so, 18 points is a small price to pay.
And I don't think a couple stamina per attack is really going to starve anyone out of stamina. It's certainly magnitude less stamina than having to prone something with cmans.
As for encumbrance, me being a human doesn't magically make me immune to it, either. I leave boxes all the time because of it. But for +40 eTD I would literally pay billions of silvers for - an amount that I would NEVER obtain from loot gains, and certainly a lot more expensive than a weight reducing bag.
And yes, I have not forgotten the penalties for those cmans as a small race. Just like I have not forgotten about penalties large races have, such as hitting smaller critters (Like one that I hunt on a daily basis - Cerebralites.).