I don't think they allow that. Their TOS, section 6, says: "(1) The Customer expressly assures that the provision or publication of web page content created either by himself and/or web pages created for him by the Provider based on information provided by the Customer neither infringes German law nor any other law applicable in the Customer’s country of residence, in particular copyright, data protection and competition law. Furthermore, the Customer assures that the contents provided or published by him/her are not contrary to common decency, do not contain pornographic or obscene material, incite racial hatred, violate human dignity, endanger children or adolescents, or are insulting or discriminatory. This also applies to websites of third parties to which the Customer creates a link or has a link created.
(2) If the Provider is requested by third parties to change or delete contents of web pages because they allegedly violate third party rights, the Provider will immediately inform the Customer and request a statement. If the Customer does not respond within a reasonable period of time or if the statement does not sufficiently refute the accusation, the Provider reserves the right to block server access until the matter has been clarified. In this case, the Provider is also entitled to block web space packages or server or to exclude them in another suitable way from access by third parties. The Customer's payment obligations remain unaffected in this case
(3) The subsections above are also applicable for all other products offered by the Provider which are suitable for publishing data, such as VPS or colocated server." Additionally, section 11 says that "(1) The Provider concedes complete and sole administration-rights on rented/colocated server to the Customer. Only the Customer knows the individual administration-password of the server, not the Provider. The Provider is therefore unable to administrate the rented/colocated server. Hence the Customer is solely and entirely responsible for administration and security of his server, at his own expenses and risks. It is his duty to install necessary security-software and to inform himself constantly regarding security issues as well as to fix such by himself. Installation of maintenance software or other software does not absolve the Customer from this duty. It is the Customer's duty to configure his programs in such a way that they are restarted automatically when the hardware or the operating system is restarted. § 2 (5) applies.
(2) If necessary and reasonable, the Customer will assist at simple configuration changes, such as entering the login-data anew, or simple changes of his systems." So he would be, it seems, completely on his own when managing the server. That requires an intimate understanding of Linux and the software that users want to run.
"On two occasions I have been asked [by members of Parliament!]: 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out ?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question." — Charles Babbage.
My Github