In most places that teach bioinformatics in the UK, and I believe in most of europe, bioinformatics is a sub-specialisation of biology, not of computer science. This may also be why it would not be regarded as a professional degree - most undergraduate teaching in bioinformatics in Europe approaches it from an academic, rather than a professional direction.
1) "Is Bioinformatics a Professional Degree" - See Chris's response.
2) "Should Universities offer it at the Undergraduate level?" - I think a well-rounded education is essential; students shouldn't only take courses in bioinformatics -- those should be elective courses. Students need to take core courses in discrete math, algorithms, systems, programming, etc.. Whether the degree they earn itself is called Bioinformatics or Computer Science or something else, doesn't really matter.
3) "Some people says its a minor in Computer Science" - In my undergrad (in the United States), a minor was a subject where a person passed courses in and satisfied some (but not all) requirements for the major. E.g. some people majored in biology and minored in English. In that sense, it wouldn't be a "minor". Again, it might be an area (within a larger major area of a study) where students take many elective courses in.
As Chris said, in the US, no, it is not a professional degree. We do also have higher level degrees in bioinformatics (Msc, PhDs). I would have liked exposure to it as an undergrad. I could see a place for an introductory course in biology programs for certain sub-specialties/tracks.