I just got around to perusing the forums for morsels of info to help me on my way, and I find this thread.
Another example of why I thoroughly like this site.
I am often amazed at the quality(?) of work performed by a person paid to do a job. It's exactly why I try to do the work myself if at all possible. Most of the folks that regularly come to this site could do better work than the sloppiness you found. The energy savings you have just secured make you wonder why the previous owner hadn't done this
and the light switch mod you recently took care of. To both of those improvements, I say "well done."
As for the extra velocity of the air coming out of your vents, it had to increase. You increased the volume of air that made it to the vent registers by removing so many outlets where the blower used to push the {somewhat} conditioned air. Less leakage means more, and
better conditioned air to the registers. I'm certain there is a pleasant surprise coming on the power bill, if you can compare it to what it used to be.