I think this is a good idea, and having one person dedicated on managing releases/bug triage is important and helpful. Especially as a connection between the community, bug reports, and devs.
1) graphene-ui is a CNX project that is licensed to bitshares. Bitshares will be paying you to manage graphene. Is CNX ok with a non-employee managing their releases?
2) Will you have commit access/tag access to the offical repos?
3) The role appears to be mostly community organizing, bug triage, illustration of goals (all very important for a successful project). In the end these are just "suggestions" (although probably very good ones) of priorities. Are you the one that will say "we won't release until X Y Z are fixed?" or is it more helping articulate highest priorities from the input from the community?