A fantastic outline Hello and Welcome to TravelBlog,
I found your posting this morning and can't wait for your adventure. My husband and I are from the United States also. In 2007 we quit our jobs, put everything in storage and took an around the world trip. We did our drive of the US first. We spent two months visiting friends and family then headed to SE Asia for three months, New Zealand for one month, Australia for two months and a couple of weeks in Europe on our way back.
To answer some of your questions from our point of view.
No--- :) the plane will not fall from the sky.
We have several families on Travelblog who have traveled with their children and it went very well. I'll post a few for you to look at and decrease your fears. Neither one of you will miss work and if you have intentions of returning to work at the end of this I will warn you re-entry is a tough one because you mind will wander. You will start planning the next adventure shortly after you return.
Your physician will provide you guidance on vaccinations. Be sure to get them early as some are multiple shots--hepatitis.
Your family will grow closer than you can imagine.
[diary=280115] A summary of our trip around the world
You will want to read the Sapir Family [blogger=133493]
Michael and Faye Johnson travel with their kids [blogger=21816]
The Scott Spot
The planner
Thanks
Hi and thanks for your comments and advice! I'll be sure to read about other families adventures soon :)