sem4u - 12:18 pm on Feb 25, 2013 (gmt 0)
Google does not even read the meta keywords tag so there is no advantage of having one.
If you duplicate the meta description tag on different pages then it will not look good, as Google often takes the meta description as the snippet in the SERPs. You would be at a disadvantage of having duplicate meta descriptions as they should describe in a sentence or two the content of the page.
I would say that it is unlikely to lead to a penalty though.