#1: I personally do not have expierance with #1. I do know people who have worked and homeschooled. Both single parents and duel income families. It will require some teamwork from both of you and totally doable
#2: HSLDA has the laws for each state broken down and easy to understand, along with groups(Christian based). There is a book that a friend loaned me to read called "Homeschooling for Dummies". A very good read. You can also look up other groups and talk with them aboout homeschooling in your area.
#3: Training, is not needed but each state has laws on the books that you most follow. HSLDA has that info.
#4: Homeschooling can be as expensive or as cheap as you want it. Depends on you and what you want to use.
#5: Again, I personally do most of the schooling, hubby is a Marine. However, I do know families where hubby was better at math and he taught that. Or because both parents worked than they shared the teaching.
There are many things to look at and the big thing is that both of you be onboard with this.