Hi,
You're wrong on several levels.
First, HikaShop is used through out the world not only in Europe. So even if it was not allowing you to do that, and that it was indeed unlawful, that wouldn't mean that HikaShop Starter itself would be unlawful.
Second, you, as shop owner, are required to provide such modal cancellation form, not us, as solution provider.
Third, you can attach a file to an email even with the Starter edition by adding a few lines of code in the email notification code.
Fourth, these regulations indeed say that the shop owner is required to provide such model cancellation form, but it doesn't say that it needs to be done by attaching that form as a PDF to the order confirmation email. It merely says that you need to provide such model cancellation form to your customers. It could simply be done with a Joomla article on your website for example.
Fifth, even if you had to add a model cancellation form with the order confirmation email, you wouldn't even need to attach it to the email. You could just change one of the translations text of the email notification to add a link to the PDF on your website. You can do that with a translation override, so you don't even need the Email edition interface or to add any custom code.
Sixth, the exact details of these regulations will be detailed by each country with implementation laws, so some details can vary from one country to another. I would recommend you to contact your lawyer if you want to make sure that you setup your website and business properly for these regulations.
I hope it helped cleared your doubts.