L.R.
I'm a GS leader (just finishing our fifth year).
Please talk to some other leaders rather than your friend. I'm sure she's great as a leader, but honestly, your post makes it sound like you have her on quite a pedestal and feel you won't be able to live up to her example and be a leader just like she is.
But you do not have to be the same kind of leader she is! One great thing about Girl Scouts is that the leaders have huge flexibility in what they do, how often they do it, etc. Some troops do nothing but camp; others do nothing but craft; the best ones mix things up a lot. Talk to lots of leaders and you'll find very laid-back troops and very active ones; troops that meet each week and troops that meet once a month (especially at Daisy age, see below); troops that have girls who are all from similar backgrounds and troops that are very diverse.
And one very important point missing here: Your K daughter would be in Daisies -- the very youngest (and therefore simplest) level of GS. You would not be expected by anyone, not other leaders, parents or the girls themselves, to be out rock climbing, river rafting and doing award-winning art projects with these little girls! You will have a lot of support just from using the GS Daisies materials and can use those to plan everything you do for the year. Try it and if it doesn't work -- stop when your daughter moves on from Daisies (which is K and 1st grade girls).
So go for it, but take a deep breath first and put those "million ideas" into a priority order, and check that they are realistic for girls of K and 1st grade age, and that they are realistic in terms of what families will commit to doing. Don't get into a pattern where you come up with a huge list of things for the troop to do, then feel let down when parents say, "Sorry, Sally has a soccer game that afternoon" or "Our family is traveling that weekend." In other words, be aware -- as a self-described "head-honcho" type -- that it's the whole family's schedule, not just one girl's GS commitment, that affects what the troop can realistically do. I'm NOT saying "Don't be ambitious" but I am saying, "Be age-appropriate in your expectations for this level of GS and be aware that you need parents' help, even if you don't want a co-leader." (As someone who is a co-leader, fully sharing responsibility with another leader, I would not do it alone for the world -- we mesh perfectly and it makes doing this SO much easier and infinitely more fun.)
And don't let your friend's activities drive your own. She is working with older girls and they get to do more and different things (and they also should be driving more of what the troop does--if your friend plans everything and arranges everything, she shouldn't; by now her girls should be planning how to spend their own cookie money, researching their own field trip options, voting on what badges to earn, etc.! But you would not have that going on in Daisies.)
Housekeeping: Remember that you'll have to go through a school coordinator or a GS service unit to get organized. The service unit (you can find them through your nearest GS Council office) will tell you how to get started and will help you find and register girls.
And remember that your time will be required for some training -- you can do most of the basic training for troop leadership online, but if you want to take girls camping you must do camping training that usually requires you to be gone overnight, camping with adult trainers. (This is where having great parents helps: Sometimes parents, rather than leaders, will do the camping training and are the designated camping-trained person who must go on all camping trips along with the troop leader.) Also, you need a troop first aider with training approved by GS; a parent can do this too but must be able to be at certain things (it's easiest if the leader is both camping and first aid trained, frankly). I know it sounds rule-bound, but it is all for girls' safety and to protect leaders as well. I LOVE the GS training I've had (leadership, camping, first aid, and challenge courses and zip lines etc.) and truly believe it makes for better leaders and better troops. But factor that into your commitment. You probably only need the simple, entirely online "101" training for troop leadership to start, and then first aid. The rest is optional, depending on what you want to do!
Look on your GS Council web site to see if they have information for people who want to be leaders. Don't hesitate to call or e-mail your Council with questions.