Wouldn't change anything for scoring, or scenario books, or anything, as it's exactly the way it is now. Just saves time by not forcing the automatic kick first. Your decision to go for 2 or not would be exactly the same, and for the same reasons.
Was going to mention the Snow Bowl, so I'm glad Alidar
brought it up. The inability to kick and the choice to go for 2 (except for the one one miss, which was hilarious) made that game much more interesting.
The other side-effect of awarding all TD automatic 7 points is that the player who scores the touchdown now scores 7 instead of 6 on stat sheets. We've got decades of data for players who score touchdowns, and each one of those guys gets 6 for his TDs (and 2 for any 2PC). Kickers get 1 and 3 for their goals, and are typically the scoring leaders for teams when they play over multiple seasons. If the problem is that kicks are too automatic, either make the kicks harder or eliminate the kicks and force the 2PC (like college does in 3OT). Don't award 7 to the scorer.
I like the idea of the scoring player having to kick the PAT. You could also make it like rugby, and force the kick to come from perpendicular to the point at which the ball crossed the endzone, instead of all the kicks being straight-up line drives down the middle. That might change scoring strategy, too (i.e., you score a TD right over the pylon? You've gotta kick it diagonally from the sideline toward the goalpost).