I agree with Deb.
Answers to your questions:
1- preferably, no. Because the end effect is a column of burgundy with a skirt and a shirt thrown over it, as an after thought, or as if you were too cold.
2- For this occasion, I would go for the beige blouse with a beige cami under it, skipping the burgundy turtleneck. You could wear some pearls too? (Or is that too dressy?)
3 - From this pic in this light, the tights do not look hideous at all with the coat. It's a gorgeous coat BTW. But you have to see in daylight if it clashes.
I like the fashion forwardness of the burgundy turtleneck worn under the flower shirt. But in terms of proportion and texture, given it brings a lot of (good) attention to you top half, I would wear this with pants. My first choice would go for wide brown pants+heels, but do try it with skinnies, it might look awesome.
I understand the pattern mixing from flower shirt with the skirt's material, and I think it is quite interesting; however, not with the turtleneck in that case; because there already is a contrast between the turtleneck and the shirt, so another contrast is distracting.
Tomorrow, I would wear the skirt with the brown tights and brown booties, it creates a very nice line, without drawing too much attention to your legs, which are fantastic, but just sayin' due to the nature of the event.
Please post more creations!