In addition to those matters specifically referred to in §§ 14.4 through 14.7, the Commission may, after notice and opportunity for hearing in the matter, deny, temporarily or permanently, the privilege of appearing or practicing before it to any person who is found by the Commission by a preponderance of the evidence: (a) Not to possess the requisite qualifications to represent others; or (b) To be lacking in character or integrity; or (c) To have engaged in unethical or improper professional conduct either in the course of any adjudicatory, investigative or rulemaking or other proceeding before the Commission or otherwise. With respect to the professional conduct of persons licensed to practice as accountants, “unethical or improper professional conduct” means: (1) Intentional or knowing conduct, including reckless conduct, that results in a violation of applicable professional principles or standards; or (2) Either of the following two types of negligent conduct: (i) A single instance of highly unreasonable conduct that results in a violation of applicable professional principles or standards in circumstances in which an accountant knows, or should know, that heightened scrutiny is warranted. (ii) Repeated instances of unreasonable conduct, each resulting in a violation of applicable professional principles or standards, which indicate a lack of competence to practice before the Commission.