Did they fix the Wall of _____ spells, and did they enable magic use from horseback?
1.7 adds no new features to speak of, so magic use from horseback is not enabled. As for the wall spells...I can't check, as I have the USKP installed and I believe it fixes this on its own. Someone else will have to check that one, but my suspicion is that no, they're not fixed.
Edit: Also did they fix having Sarena as a follower making the Vampire Lord drain life spell useless?
Dawnguard is not out for PC. We cannot test this.