Responsibilities of the editor(s)

Prospective editors of new journals should be senior researchers, e.g. chaired professors. Their responsibilities include:

compiling a stellar editorial board
soliciting initial articles from editorial board members
together with editorial board members, solicit on an ongoing basis a steady stream of articles
adding peer-reviewers to the peer-review database
triaging submissions into "decline without peer-review" and "send out for peer-review"
assign peer-reviewers
oversee the peer-review process, including making sure that reviewers respond within the deadline set
ensure the quality of published material, through peer-review, own comments, and editing
an editor edits, i.e. must have the ability (i.e. superior skills) and time to write and rewrite sometimes poorly written manuscripts is a must
prospective editors should be warned that this is a time-consuming and largely honorary "job". Do not endeavor to start a journal if you are not prepared to spend at at least one day per week on journal work over the next couple of years !