The only problem I see with using the word "may" instead of "shall" is that you are saying that it is possible for someone to not receive ANY punishment whatsoever in regards to the offenses listed. The verbiage suggested by Larry and Alices states the following:
Any member violating the bylaws of this organization, its Constitution, or its Code of Ethics, or engaged in conduct unbecoming to a member, or engaging in conduct prejudicial to the welfare of the organization, may be subject to expulsion or other disciplinary action.
From many years of enforcing building code I can tell you that the word "may" is not an enforceable word. "Shall" leaves no room for latitude. It is something required to be done. IMO the current wording is fine because it states that a punishment shall be levied, whether it is expulsion or other discipline. This is fair because it gives the governing body the latitude you need to levy a punishment that fits the crime. Check out the current language:
Any member violating the bylaws of this organization, its Constitution, or its Code of Ethics, or who has been convicted of a criminal offense, engaged in conduct unbecoming to a member, or engaging in conduct prejudicial to the welfare of the organization, shall be subject to expulsion or other disciplinary action.
So it is the intent of this rule to either expel or discipline a member who violates the code of ethics, engages in unbecoming conduct or grieves the association as a whole.