Hi momofm&m-
First, I'm sorry that your experience wasn't a good one. I don't know the specifics of what has happened to make you feel this way. It is possible, that the volunteers in the upper levels of your state and local PTA have forgotten their mission statement and what PTA is all about. Just like you, we're volunteers with lives outside of PTA. There are those of us in the higher levels that do focus on helping our schools and our children. I have been fortunate to work with many in our state that have maintained that focus on children and am grateful for it.
Like Rockne, I would also hate for you or anyone else to be soured on parent involvement.
My opinion on your questions is this (and because I am PTA you can take it however you like, it's just an opinion)
However, I do think that it is a conflict to start one while disbanding the other (before you vote to dissolve) whether you are leaving PTA or entering it. I have said in other posts, although legally, you can do it, ethically speaking (or morally) in doing it as your bylaws suggest and dotting the i's and crossing the t's. It just seems to be the right thing to do. You aren't sticking it to any of the people you named, in doing it the other way. It generally boils down to numbers and they'll move on. However, you'll have the satisfaction of knowing that regardless of your anger, you acted fairly and perhaps better than those who caused your anger in the first place. As a council person, I have only asked that the few who have dissolved, follow the procedures and I have never acted unkindly towards those that were above board.
Lastly, it is quite appropriate to have open discussions at your general board meeting and to notify your membership that this is the purpose of the meeting. And as your bylaws will likely require, that both sides be represented (generally we have had an outside PTA rep, and an outside PTO group leader present their pros. Also, at least for us, recent bylaw changes require a state representative to attend this meeting) It is also more than appropriate to ask them to act kindly. No one wants to be involved in anything ugly and I know that some people's experience has been anything but pleasant. I think that has hurt us but again, we are all just people too. It just hurts those of us who are trying to do what we're supposed to do.
No matter what the end result, you're still a group of parents/caregivers trying to make this better for your children. One isn't better than the other, just different.
Perhaps, if it isn't too late, you can even effect change in the PTA at the higher levels in your area. maybe just telling them how you feel could put them back on track. Remind them of why they started with PTA in the first place.
Whatever the outcome, good luck to you.