Hope Angie doesn't mind if I jump in first!
What length of open or button sweater-cardigans allow your legs to look long? I'm pear shaped but love an almost knee-length sweater, before I go shopping I'd rather know what looks best which isn't always our 1st choice.
I think it really depends on individual height as well as body type, plus other individual variables. Being rather pear-ish myself, and 5'9", and not model-thin, I don't like longer (below the butt) sweaters. At least on me they tend to cling to and accentuate the wider bits, plus I only see my lower legs (which are not super shapely), so I also look a bit stumpified. A higher hip or cropped length gives more focus up top. Again, it depends on the individual. A shorter sweater on a long torso may make someones leg's look shorter.
Also, I am a redhead, fair skin, blue eyes and recently purchased a cardigan (mid thigh length) in a peach/orang-ish but other than black top/pants what color choices do you suggest?
I'll defer the Angie, and maybe other redheads in the forum can chime in.
Are tucked in blouses preferred more these days say for an office skirt or hung out with a belt over it?
Tucked for the office unless a business casual environment. And a straight hem. Somehow a regular shirttail (curved hem) over a skirt, in an office, looks to casual to me.
Last one, are nylons preferred when it comes to wearing dresses/skirts to the office?
I am old school. So, yes. But again this depends on your industry and specific office norms and geography. I don't know if you actually have a job in hand. If not,at least wear stockings on your interviews. At that point you can also scope out the other women in the office, and find out about the dress code.
Also wondering this re; more formal occasions-going out to 5 star restaurant, etc.
I think bare legs are ok for going out. At work you're supposed to be all about work. Otherwise, go for it.