First of all, I agree with Megaman... humans, when played by experienced players, are at least a match for aliens, if not more. Ranged attacks, by common sense, allow more players to attack a single target than melee attacks. True, a group of inexperienced humans can end up shooting each other as much as the aliens, but for the sake of argument let's assume both teams are reasonably competent.
But back to the main point of the topic: no restriction on jumping. Even if the humans were underpowered, I don't think this would be the way to solve it. Firstly, would jumping be adequate for the kind of dodging you're referring to? Secondly, you would get the bunny hopping and other such things that the stamina system hopes to remove. Overall, I disagree that unlimited jumping would improve Tremulous.
What I would propose if humans were found to be in need of dodging abilities: don't make unlimited jumping, but maybe buff jumping so it would be better for dodging. Also (I don't know if this has been discussed in earlier threads) add a roll system.
I don't think human's dodging need upgrading, though.