... Thank you for writing to us at the Community Tool Box with your detailed question. We understand and appreciate your deep involvement and personal caring for your organization.
As we read your question, we think this is a case where your group would benefit from a retreat, hopefully off site, with plenty of lead time, prep time, and retreat time, and with the well-communicated, set-in-advance, and agreed-to goal of sorting out some of the current key issues facing the group, some of which you name. If members can get behind this much, that's a definite plus.
You would want a good facilitator, or session leader. There are plenty of them. It's not our role to recommend specific names. But what we can suggest is that your leader should be a highly-regarded neutral person, acceptable to different interests within the organization, and perhaps best chosen by a smaller group representing those different interests. This seems consistent with what the questioner has in mind. To hire the right person might cost some $$, but this is a situation where it could be well worth it.
We hope these suggestions may be useful to you. Thanks again for writing, and all best wishes for many continued successes for your organization in the future.