Question 1: Should I wear a black cover-up instead of a red or ivory (some people I asked IRL suggested ivory or white)?
Reply: I would go with the red if you wear some colourful shoes. If you wear metallic or black, then i would go with purple or black cardi. A white cardigan with black dress is a way to sharp contrast.
Question 2: What do you think of pairing the dress with black opaque or patterned tights? How about grey tights?
Reply: Both black, grey AND patterned sounds great. I would go with patterned as the other two options could be a little boring.
Question 3: Black cardigan/jacket/bolero with red shoes? Yes/no?
Reply: No. IMO, a whole-black outfit with one red element is also a too sharp contrast. If you use a purple/other colour cardi with the red shoes it's OK. Remember a black purse. Shoes and bag in a colour will be too matchy and/or clowny
Question 4: I like the first dress better than the 2nd, mainly because it's more suitable for my height (I'm only 5' 2"). Can the above mentioned suggestions work with the first dress as well?
Reply: Yes, i would think so. I don't know the price on nay of them, but the first one looks way cheaper than the first one.