Switching the leadership team

The problem: My boss and I are switching out the entire divison leadership at a single time.  How do I maintain the credibility that I've established and build a team, while maintain the focus effective operations in the short-term?

My current plan:
1) Support my boss' decision to switch much of the leadership.
2) Once the switches have all occurred: sit down with my directs as a group (Team Building meeting), redefine our mission, goals, desired endstate and begin coming up with common expectations.
3) Encourage outgoing directs to listen to the "How to Resign" podcast and implement many of those actions.
4) Begin O3s with incoming directs and encourage them to have them with their directs
5) Hold a Skip-level Meeting in which we address these issues.

The background: I was brought in to take over a divison that was suffering from very weak leadership.  I joined the division about 2 months ago.  In fact, the executive that I replaced was fired.  He had created an atmosphere that was tolerant of sexual harassment, was openly insubordinate (and encouraged that behavior in his directs), frequently back-doored his peers, and didn't invest in all of his directs.  To his credit, the division was effective in meeting its goals, operationally.
The plus-side, I can only move the division "up."

Since joining the division, I've seen a marked improvement in "attitudes" as I have heard less frequent complaining about superiors, operations, and requirements.  We've maintained our results focus, currently with a 100% efficacy rating (the highest in the entire organization).  I have not fixed many of the issues though, including building a sense of urgency (I try to affix a deadline to all tasks and give feedback if it's missed), and I haven't gotten the division to meet all of its reporting requirements yet. 
Much of the division's leadership (nearly all of my directs) were scheduled to switch out soon, regardless--due to promotions and developmental experiences.  Still, my boss has decided that he wants to speed up the process, have me additionally move a skip internally, and fire a direct for poor performance.  All told, seven of the top eight positions are switching at the same time.  Now, three of those switches are internal, so there exists some continuity of personalities and relationships.  I do respect the decision to move people out of jobs where they're not performing well.

To further complicate issues, My division is spread across five sites (nine provinces) and we have very little communications infrastructure in place. 

Thank you very much for any advice that you can provide.  I am really looking to assist the division in its move from good to great (and I know that Jim Collins says that first you need the right people on the bus--in the right seats, and the wrong people off the bus). 

Regards,
Andy