Being a professional or being professional?
The questions conflate two ideas, one about 'being a professional' and the other 'being professional' (unfortunately the word 'professionalism' is used to describe both). An exercise I carried out a few years ago with a group of mid-career doctoral candidates was to consider first what it means to be a professional, then secondly to be professional or act professionally. The difference in the two lists was revealing.
Being a professional suggests things such as being qualified (however defined) and practising in a definable area, having expertise based on a deep level of knowledge, and having a commitment to the area of practice - possibly (but not necessarily) through being a member of a relevant professional body. This is essentially about occupational identity and status.
Being professional on the other hand is about how one chooses to practise, and is about judgement, principles and ethics.
Ideally, but certainly not always, the two things coincide.