I did the reading of the scroll, got the dragonrend shout. Long story short, Parthunaax is now a pile of bones.
I think I hit him trying to get a lock on Alduin. Future consequences? Besides the Blades being happy.

One of the consequences is that Arngeir and the rest of the Greybeards are angry with you... Other than that, nothing.

Good, he deserved it. (awaits hate mail...3..2...1...)

I can't recall any consequences other than what you've already mentioned. But I'm sure someone will point something out.

That's definitely something I love about this game, anything can happen. Trying to avoid something doesn't mean you necessarily will.

None that would actually matter. Greybeards won't talk to you anymore, so they won't give you the locations where you can get more shouts ( funny that I learned about it after getting almost all of them ) and Paarth won't give you ( for obvious reasons ) one of the 3 buffs which aren't so good to begin with.