Thank you for sharing your question with the Wefugee community!
First of all, I need to say that I am not really familiar with the mentioned "European Agreement on Transfer of Responsibility of Refugees" (the regulation was made in the 1980s by the Council of Europe and it is, as far as I know, referring to people who have been granted international protection; the Council of Europe is nowadays also not the most relevant institution regarding European refugee law/regulations). I assume that your case will be relevant for the Dublin procedure at first place. As I understand, you are a rejected asylum seeker in a European country? Then, unfortunately, you can not simply transfer your application to another country. However, if you are able to marry or not is not necessarily dependent on your (missing) residence permit.
Please feel free to get back to us if you want to discuss your case further.
All the best,