I don't want you to reveal more than you absolutely have to, but some of this sounds like the ordinary adjustments that every dean has to make. This statement for example:
Within several months, it became very clear that there was a great deal of petty bickering and jockeying for power. I have come to realize that certain key persons in this college are real back stabbers.
That's fairly standard in most organizations. The question then becomes what, if anything, do you do about it.
Of course, my concern is for myself, but they are also ruining the reputation of the College in the community and hurting students.
I think retaining your attorney and preparing to return to the faculty are fine if your only goal is self-preservation. But you need to decide whether you feel it necessary to take these people down because of the harm they are doing to the students and the college. If you have examples of concrete and specific harm that they are doing to students, then you should certainly address those, either directly or with their supervisors as appropriate.
My instinct would be to serve the greater good, and stand and fight. I've been stabbed in the back before, but that happens in faculty jobs as well as administrative ones; moreover, that's why they pay me more money. And if you have tenure then there's a limit to the amount of damage they can do to you.
Consider also what they will do if they are not stopped. Will your successor as dean have a better time of it if you leave them in place? It's possible, of course; there may be another person who is better equipped for this kind of fighting.
If they are corrupt and perpetual back-stabbers then they will have enemies besides you. Build alliances with the people they have wronged, either to topple them or to take action by working around them. Since they are "entrenched", working around them may be the best way to go. You can give them some areas of authority so that they leave you alone, or isolate them by soliciting their advice and then ignoring it, or assign them to search committees or other bodies to sap their energies.
Naturally, you need to filter this advice through the layers upon layers to which you allude. I can easily think of some nightmare scenarios that would be too difficult to fight, or a situation where you have something to protect (such as children) that leaves you incapable of pursuing this.
You may want to read the preface to a book called "Failing the Future," by Annette Kolodny. It is the best short introduction to deanship and the toll it can take on a person. If you need a longer book to read, try "Academic Deanship" by David F. Bright and Mary P. Richards, which contains plenty of advice about how to deal with difficult situations.