Secretary2016 also posted similar questions here. Perhaps additional responses should be made in that thread instead of repeating the same information in two threads.
If a ballot vote is required in the bylaws, then a ballot vote must be done. If a ballot vote is not required, then the chair simply declares the candidate elected.
In RONR, rules protecting absentees cannot be suspended, even by unanimous consent or an actual unanimous vote, because the absentees do not consent to such suspension (see RONR 11th ed., pp. 263-264).