+1

With the most recent buffs to veigar i agree with your skill sequence. I'm a fan of pumping the farmable spells early game. Also your summoner spells are on point for midlane. Any other lane you don't need it and should take flash like you said. But never exhaust (let someone else take it)

I don't really agree with saying that veigar doesnt need a mana item AT ALL just because of his passive. You dont want to run dry late game when your nuke is needed the most. Your passive allows you to keep spamming one spell (mostly for early game baleful strikes), however late game you are going to need to constantly spam all of your spells.

So I give you a +1 and then a -1 O.O .... so I'll just not vote :P

Also you could use name of spell/item to make your build a little more easier to read.