Hey there!!
Dobermanns have to be muzzled and always kept on a short leash in some parts of Spain, in others they don't, depends on the state you're living in.
For example here in Madrid where I live Draco isn't included in the dangerous breeds list, but he is included in Andalucia for example, stupid I know.
The general public is scared of Dobermanns, even more if cropped and docked. So expect a lot of comments like "Those dogs are dangerous, their brain never stops growing and they go crazy and kill their owners!" "They lose their sight and sense of smell and attack their owners!" I suffer from stupid comments on a daily basis, and he isn't even cropped. People are so ignorant, just don't listen to them.
They can participate in sports as far as I know! I've seen multiple cropped Dobies doing stuff such as IGP, Agility, Obedience...there shouldn't be a problem with it!
You can ask me anything you want, and welcome to Doberman Chat!