Hmmm, I don't know about this advice.
1. I suppose you mean look at feet when placing them?
2. I think there might be too much variability to make such a generalization. My toe/heel plane tends to be perpendicular to higher when climbing.... Also, pointing the toe will often be necessary when makign a reach. And if the heel drops too much, your foot-to-rock contact strength will diminish. I'd say perpendicular or higher.
3. Often true, when driving off of that foot. But again, so much variation. Often you'll want the knee past the foot for maximal drive and for getting all weight on that foot, especially on high-steps.
4. maybe on slab to vert? While on both feet?
5. absolutely.
But try it all, and see where it takes you.
Sex chococolate: Stupid fuck. Of course this is a generalization! Its just good primary technique to start with. Its not like I made it up, its technique advice I've taken from climbers who climb a hell of a lot stronger than you or me. Dumb ass.