I did sleep about 5-6 hour a night when I was at school... can't quite do it anymore. Overall, I notice how my body just can't handle some things I used to pull off easily when I was 20.
Plus, I hardly ever studied, other than the night or two before exams. I have a good memory, and also I get things - so I don't need to read something twice to understand it. And I don't need to memorize all the details because if I understand the logic behind them, I can figure them out, so why waste time memorizing? That helps use time more productively both in school, and later on life.
Pretty much the same as with research experience.
Business acumen, analytical thinking and communication skills are a lot more important. Though positions like my current one are not entry-level positions, so you can't get them out of school anyway.
Business intelligence, which means market and competitive analysis to support commercial, scientific, and new business development strategic decisions. Basically, I read a lot about what's going on - be it clinical studies reports, pre-clinical publications, patents, government legislation or regulations, competitor companies' financial reports or press releases, trade journals, internet - a lot of different things. Then I decide what's important and what's not and analyze it and then talk about it with people who will need this information to make decisions. Or, alternatively, people who have a question come to me and ask me to analyze the situation. All kinds of questions from simple and straightforward to very complex. Also it is a very collaborative position, so I interact with almost every department within the company and get their input, or provide my input for them - so I am in the middle of all things and wear a few different hats. That's what makes my job so interesting, and also so challenging. My current position is the third one I hold in this field, and all three have been a little different, but all three I really loved. To me, it's important to enjoy my work, so I am quite picky in terms of both job descriptions and the company climate - in a wrong climate my job would turn from a dream job into a nightmare where I would feel useless and frustrated...