The facts that you describe may not rise to the level of alienating conduct that would establish parental alienation per se, though it really does depend on the totality of the specfic facts adn history of this particular case and the particular judge that hears the case.
What you seem to be describing, at a minimum, are violations of the existing custody order. The remedy for that is to file a Rule to Show Cause against the custodial parent for civil and/or criminal contempt. You can also file a petition for a modification of custody based on these same facts.
If your fiance has not yet contacted his attorney to discuss these issues, questions, and concerns, then I would suggest that he do so as soon as possible. His lawyer will have more intimate knowledge of the facts and history of this particular case, as well as knowledge and experience with the local judges that may be hearing this case.
This response does not create an attorney-client relationship and is intended for general information purposes only.