To answers your questions:
1) General review, yeah it's okay
2) Step studying, nah. You need to know details. Medscape won't work for that.
3) Broadening knowledge of medicine, I guess, but it is woefully inadequate. If you want a broad stroke of a disease or treatment it'll give you that. If you actually want to learn about a disease (and want to impress someone on a rotation), you need a systematic review and those are on PubMed.