1. Yes, if it's something that fits really well and I love it, I will buy it in 2 colors or more. I'm a tshirt girl, and they are hard to find that actually look and style nice.
2. The link isn't working!! But, I would say, it depends on your coloring what feels good on you. To me, very bright colors wash me out and make me feel too exposed, but they look great on other people. Seasonally, colors in navy, white, coral, gray, turquoise and yellow are all very popular.
*okay, link is working now. Tough choice! But think, you can always get a black cardigan anytime, but that color nude is pretty rare. It would be a great spring/summer color. So just think about how you would wear it.