What preconditions do I have to satisfy to be able to register a .de domain?
When you register a .de domain you conclude a contract, so you must satisfy all the conditions that apply to the conclusion of any sort of legally binding contract. First of all, that means that you be capable of entering into legally binding rights and duties, which any natural individual or legal entity is certainly capable of doing. Secondly you must be capable of conducting business or you must be effectively represented.