Regarding moves/attacks:
I found it weird that I could use my Volcarona (61) that knows Fiery Dance (100) online. So I proceeded to test a few combinations out listed below (all were shiny...that shouldnt change anything though...). They had other filler moves, like the Pledges moves and TMs, and level up moves(Rollout, Assurance, etc). But I was just testing the highest level moves (Flare Blitz, Hydro Pump, Leaf Storm) mostly. Did not try with Egg moves. Met conditions were as if I got them from Prof Juniper.
Conclusion:
-The 1st stage (Tepid, Oshawott, Snivy) can learn moves higher than their current level if they're lvl 10 (or below that)
-The 2nd stage (Pignite, Dewott, Servine) can learn moves higher than their current level if they're lvl 19 (probably 17 because that's when they evolved).
-The 3rd stage (Emboar, Samurott, Serperior) can learn moves higher than their current level if they're lvl39 (probably 36 because that's when they evolved).
-This is information is not -that- useful because Nintendo WiFi brings the levels to 50 or 100. O_O