So what I'm getting so far on point #1 is that mulching blades are good year-round, and there's no real downside to using them. Only potential benefits. (Unless I'm missing something).
And on point #2, what I'm hearing is that fall cleanups to fully remove leaves vs. just mulching over several times is more a matter of aesthetics. I.e., even a large volume of leaves can be mulched and left on the lawn, and they'll actually be beneficial to the soil through the winter. It's only a matter of whether a home-owner dislikes they way they "look." I personally enjoy the look of natural fallen leaves. My only concern at all on point #2 is whether there's any truth to the fact that leaves could be harmful to the lawn or suffocate it. But it sounds like "mulched leaves" don't fall into this category based on the replies so far. Is that fair? I'm guessing with larger leaf volume, I'd have to mulch them more often as they come down to prevent large buildup.