I see in your schedule that you begin with K calendar (and ECC things), but you have K activities scheduled later in the day. I have just one other suggestion for you to try. I have heard or read many times...on this board, in magazines, on blogs...that it often works best for you to devote some time to the youngest kids first. I have found that to be true! You should certainly try the schedule as you have written it, but if you find that something isn't working, you may want to try doing the K stuff with your K'er (maybe pull in the 3 and 1-year-olds, too) first thing in the morning, or maybe right after Bible. Get your older kids going with some independent work while you work with the littles for maybe half an hour to 45 minutes on the K activities. Then, the littles can go play while you work with the older kids. Of course, there will be interruptions in your day as you need to attend to your little ones, but I find that my youngest is fresh in the morning, and if I work with him first, then he is free to play the rest of the day, and I am more free to work with my older kids. Just something else to think about and maybe try at some point.
One other thing that has worked well in our house has been for us to do some of our "together" work, such as history or geography, and then I give my kids a list of their independent work, and they can choose which subjects they want to do when. So, instead of having a language arts hour or a math hour, we just have independent work time, and I am available to help them as they work on their subjects, but it gives them some choices as to the order in which they want to complete subjects. Again, just an idea to consider when implementing your schedule. It might help you, too, since you don't really like schedules, but you'll have a general framework for when you are to get certain things done. For example, here is how our schedule looked last year as we did EX1850:
9:00--Bible and hymn
9:30--Independent Work (handwriting, reading, book basket, spelling, Rosetta Stone, art, etc.) and mom works with preschooler
10:15--History (together)
11:00--English (3rd grader) & more independent work time (7th grader)
11:30--Lunch break
12:30--Science
1:30--Math
End around 2:30 or 3
This schedule just gave us a general framework to follow. Sometimes we were off on our times, but that was okay. Sometimes certain subjects required a bit of instruction or help from me, such as art or reading, just depending on what we were doing that day, and other days those subjects were independent for my kids.
Just a bit more food for thought for you.

You'll play with your schedule, and you'll find what works for you and your kiddos. It's different for everyone. You just have to tweak and try some different things.