Manager vs. Verwalter
To be added: a "Manager" in German has often a very bad connotation. They are overpaid, incompetent, irresponsible, arrogant, encroaching on the rights and competences of their appointhers. A "Verwalter"s as an individual could be all of that, too, but does not normally have these connotations, rather contrary ones.
The English term administrator in the context of computer systems and networks cannot be translated as "Verwalter", only as "Administrator".
Thus I do not see the above choice as a lucky one :-)
Administrator is used in the context already for another role, so not available.
I don't agree about the connotaion: Manager is used in the press not with a bad connotation as far as it is: daily press (spiegel, FAZ, Zeit, Handelsblatt, business categories, business magazines, Wirtschaftswoche). Typical usage in articles is "Topmanager", "Spitzenmanager". SPON runs even a column to emphasize good performances of the middle management ("Nach Dikatat verreist"). One of the major business magazines is named Manager (http://www.manager.de/).
Exceptions are commentary ("Kolumnen"), especially of left wing bloggers (SPON without Fleischhauer). The other exception is reporting on law suits on managers.
On Wikipedia they use "bureaucrats" for a special role ;-) there i would agree on a negative connotation when i never heard the word with a good connotation :-D Did you?
What about a more positive Word which stresses the leading function either: "Leiter"? Or, cause of managers relation to projects on iNaturalist, it could be more precise: "Projektleiter"?
I think most would like a role with that name, probably more than "Verwalter" and even "Manager".