Guild problems caused due to the seniority principle

I am bringing this topic to the forums as suggested by OOO support staff
because they have neither the tools nor policies to deal with our problem,
which in summary looks like this:

Our guild was created when SK went public. The original guild masters and
founding members retired soon afterwards, leaving two second generation GMs
behind which then rebuilt the guild from scratch. Recently, one of the first
generation GM's started playing again in the sense that they would idle in
chat and let everyone know who is boss. To make it utmost clear, this person
never contributed anything of value, but made it clear that because they
"had the idea" (to create the guild, not actually the funds) and is superior
in command, they are entitled to special privilegies. The details of this
are, of course, a bit more nuanced, but not relevant to the problem.
In the past, we would have dealt with this by simply creating a new guild,
but since the introduction of guild halls and the fact that we sank millions
in ours, things are no longer that easy.

So much for the story, the actual problem looks like this:
The seniority mechanism is deeply flawed and has been so from the beginning.
There is no concept of handing over control when senior members retire,
hence causing "slot rot". This was already an annoyance back when
memberslots were capped at 100 (we frequently hit that limit), but the
bigger picture is that this damoclean sword allows ghosts from the past to
return at will and force their will upon everyone else. Effectively, OOO has
created an environment in which individual players can grief or extort other
players, by holding their community investments as hostage. This is especially
troublesome for newer members who do contribute generously to the treasury
and had, at their time of signing up, no idea which personalities lie behind
dormant names.

Please understand that this is not a call for help and it is not a game of
name and shame. By the time, this gets published, our guild has already
fallen apart, since key members are leaving in protest of that GM's behavior
and dragging others with them. We are not in need of suggestions of how things
could/should have been handled. For us, it is simply to late.
As of now, we have explored all our options, including a very lengthy, but
otherwise inconclusive chat with OOO's support staff. They can not help us
as they are lacking the means (technically and policywise) to do so. The
sole point of this thread is to collect suggestions on how the system can be
changed to prevent such situations in the future.

from my former GM ; ;