A vice is an unhealthy behaviour. Often food related. They are unhealthy not necessarily in the nutritional sense (though this is often case), but in that they are a response to stress. The key to recognizing a vice is negative effects that arise from it. I run regularly not as a vice, but as an activity that enriches my life. If I start consistently overtraining, then it's time to ask "what am I running from?"
For me, alcohol was a vice. The 'stress' was having to think about things. When I'm drunk, things just flow. It's easy. It was away of avoiding really engaging with situations. It took me a long time and an international relocation to decide that I was ready to tackle life without alcohol. It's harder, but in the really rewarding sense. I have more stimulating conversations, I'm actually more creative (as opposed to thinking I'm more creative), I think more.
Yes, but none you would consider traditional vices. I've been sleeping through my first alarm recently. That maybe normal for many people, but I recognize that for me it is a vice - a response to the stress of finishing up a job, and too many weeks couch surfing.