Such helpful feedback and good ideas!
Everyone who suggested the patterned leggings with the dress: I was planning on wearing the grey-black patterned leggings with my black sweater dress (shorter, will show off more of the pattern) and possibly the grey one, but I'm not sure about the burgundy and that pattern.
Everyone who liked #5: I like that one too. I've worn that dress and jacket with black tights and muddy grey oxfords. The shoes match the jacket well enough when they're that far apart. I think.
Tweed jacket not going with the A-line skirt: That's interesting. I may have to work on styling this jacket (which I just picked up at a consignment store and haven't worn yet). I'm pretty sure it will work over the simple black sweater dress, but I'd like some other options.
Bonnie G: Thanks for the praise on the jackets! I sort of collect interesting jackets, with my rationale being that I wear them for teaching, but the truth is that I simply enjoy them.
The lacey blazer in 4: The consensus seems to be that it's too high-contrast with the sweater dress. This is another consignment store find that I may have trouble styling. Perhaps it might go better with a light grey sweater dress?
Socks and boots: I was practicing wearing socks so that I can fill in the volume when the boots are wider than my legs, but I guess I need to coordinate colors.