Looks Good. Why not bump up your maris otter a little more and eliminate the dry extract? This would reduce cost (grain is cheaper), put more of a personal touche on it and lead you more down the path of total recipe design from scratch in the future. Just a thought. This is how I stepped from buying kits to piecing my own together, modifying them, etc. to finally working up recipes from scratch. A little at a time. A small change here and there will show you what flavors show up or disappear, what contributes what, etc.
Most of all...have fun!
Bottled: Mild, Cream Ale
Primary or Secondary: Mild, Robust Porter
Upcoming: Robust Porter, Oatmeal Stout, English Bitter, Vienna Lager, Cream Ale, Mild