As for saying 3 damage (plus a 3/3 body) is useless in the late game, I guess we'll just have to disagree. I think Fire Elemental could easily make an appearance in this deck.
Agreed. I don't think anyone ever complained about drawing Medivh's Valet in the late game as Aluneth Mage. Lackey Shaman is likely to be an aggressive, tempo-focused deck so any board control tool that can also be used for burst is going to be welcome. It may be a little harder to satisfy the condition than "have Ice Block up" but a smart player is going to know when its correct to hold onto a Lackey for potential burst with a topdeck wasp.