To my eye, they all look ok, not dated. My personal favourite would be the chain necklace in the upper right corner of #1.
Dainty jewellery (apart from rings) seems to visually "disappear" on me, perhaps because I am relatively tall, have a prominent nose and wear statement glasses. So I need--and like--jewellery that is somewhat--but not extremely--chunky. It's all about proportions, harmony and balance.
As you have realized already, lengths are also important. Based on what I think looks and feels great on me, my necklaces are either short (but not tight, like chokers), or somewhat longer (but seldom longer than to my bust line and never reaching my waist). In fact, I have separated my necklaces in two "departments"--dep. 1 for necklaces that could successfully be worn under an open shirt collar, and dep. 2 for longer necklaces. Generally, my short necklaces are mostly worn in summer, as they don't interfere with the lower necklines of items like tank tops, tees and open summer blouses and dresses, while my longer necklaces are mostly worn in winter, as they are easy to wear over turtlenecks, crewnecks and highneck blouses and dresses. But I have no hard rules. However, I find it practical to have my necklaces separated by lengths, as this makes it easier to quickly find what I am looking for.
What looks and feels great on YOU, depends on your features (height, lines, colouring, features, etc.) as well as your clothing style, lifestyle and personality/taste. I wish you good luck with exploring the possibilities and identifying your preferences.