Rave, F250 is somewhat right. When first learning, it's really easy to have grand ideas of what you want to do, but that makes it hard to learn if you over do it, and learning is your goal for this Mr. B. kit. I started the same way with Mr. Beer, but held my "creativity" back a bit in order to learn. I added some spices to the American Ale, used brown sugar for the Vienna Lager, and bottled with maple syrup for the Irish Stout so that I could make the beer more "mine" and see how those things behave in beer. You know what an American Ale will taste like if you've ever had Coors or the like, so keep your adjustments simple to see how it affects your brew. That way you can better adjust your recipes to your tastes when you get to that 5 gallon kit (which is half the fun). Focus on practicing the proper technique for the first few too. The technique will be the most frustrating thing to get down pat as far as efficiency goes and it's the most important thing to figure out.
In conclusion, go for trying the DME addition, but keep it to that and some hops for balance for this first batch. Use an online recipe builder to help you see how much of each to add for some guidance. I typically use the Hopville Calculator, though recently it's been freezing on my browser (I think I need to update). Also, try bottling with DME, it wont have residual flavors of other fermentables that some people claim (I liked the maple syrup in my stout, it was a nice, subtle addition), but make sure to measure it out BY WEIGHT!. It's a pain in the ass but the last thing you want is to invest 2 weeks into this to get gushers and a massive, sticky clean-up on some far off, dark closet.
Analysis: Keep it Simple, Stupid (K.I.S.S), keep good notes for later, and have a blast (remember to share with friends, they'll be more likely to help you move when you're serving up such wonderful suds).
I think I speak for everyone here when I say, "Welcome to the world of homebrewing!" Have a great time and browse the site some, you'll be amazed at what you find.