European law. The Dear Rich Staff is not familiar with Irish law although we do have a limited knowledge of the trademark laws that apply to the European Union. For the most part, the same principles apply in the U.S. and Europe, and both sets of laws recognize limited rights for free speech and parody.
Barbie's case. You are correct about the Barbie doll case. Although the artist prevailed, one should also be mindful that the lawsuit lasted for years and cost hundreds of thousands of dollars. Mattel has a litigious and slightly cantankerous reputation so as a general rule, it's probably best to avoid placing Barbie in compromising positions.