Scorp. I want you to know I understand the feeling when some on the board tell you to do something, and then you feel like you did that, and then you get 2x4d. And then when you try to explain they tell you you're being defensive and should see a shrink about that. (Oops, am I venting about my own issues? LOL.) It's not that fun. I do want you to realize that you have a lot of really wise people here commenting on your thread, which means there are a lot of people who are rooting for your kids and your family.
Here is what I see. You seem to be kind of like my H. He has two modes: doormat and [censored]. There is no in between. But, in between is exactly where you need to be. No, you don't let her call all the shots. But you don't just start demanding and bullying either. What you need to be is assertive. I thought that Eric's email above was terrific. Stop waiting for your W to respond to the email you sent this morning. If I had received that email, I would be on the horn with my L immediately and it certainly wouldn't get me in the mood to negotiate or compromise.
You could send another email to her and tell her you just reread what you sent, and realized it sounded a bit more aggressive than what you intended. You can apologize for that (and even explain that this is extremely hard on you, but that you are trying to keep your emotions out of it as that is best for the kids), and then maybe say some of the things Eric mentioned above. In a nice, cooperative, but firm manner.
Also, quit it with the "she works and only sees them for two hours each night" thing. So what? Lots of people work and only see their kids in the evenings. That doesn't mean that they don't deserve time with their kids, or that their kids don't deserve that time with them. I believe you said yourself that your Dad would be around to help you during the time the kids are with you - so it sounds to me like you are both busy people.
I know that frequent transitions are not necessarily good for kids, but let me tell you of my experience with my own kids. For the first 5 months of our S, my H had the kids overnight two nights a week. But he trained tae kwon do with us twice a week. My kids really were fine with that. Then my H quit TKD. Shortly after, we went to a new schedule where he has them MORE overnights, and guess what? They miss him terribly. To them, it was more the frequency of seeing Dad than the length of seeing Dad that matters. Going 5 days in a row with no Dad is torture for my little S8. Point being, (a) 7 days is probably too much esp. given the ages of your kids, and (b) the two hours they spend with your W on the days she works probably means a great deal more to them than you think.
P.S. PLEASE Stop yammering about all the LOADS of research about 50/50. First off, I could find just as much research that says the opposite. But more importantly, the people who wrote those articles do not know YOUR kids or YOUR situation. You are WAY too stuck on this 50/50 thing. You don't need to have them 50/50 to be a great Dad. Focus on being a great Dad, and giving the kids what they need, and being involved in their lives. The numbers don't matter. Your kids are not going to calculate a percentage to see who has how much time, they are going to remember whether you were there for them, if they can count on you, and if you modeled how to be a loving, happy, self confident person. Maybe it will work out to 50/50, and that would be great. Or maybe it will work out another way that will be even better. Be open to whatever you and your W can come up with to make sure that the kids are secure and happy.
me: 44 XH: 42 M 11 years D10 and S8 Bomb drop 9/27/13 D final 7/1/14
