So let's not bother trying to guess the number of dissatisfied users out there - there are undoubtedly thousands of people who would _not_ be satisfied if they knew what Wikipedia's community is like to work with at times and how vandals can change the number "7" to the number "2" in articles without the change being corrected for months or even years. Let's just try to build a more reliable resource with a more pleasant and productive environment, one that many people will be happy working in.
Vandalism is a natural consequence of openness and popularity, the only way you're going to avoid it is by either heavily restricting who can edit or by not being popular enough for anyone to bother. I don't see what having a pleasant and non-bureaucratic working environment has to do with it. If you have any suggests on cleaning up vandalism quicker, speak up - we'd love to hear them, and we could implement them on Wikipedia rather than going to the trouble of creating a new project.
Oh, I agree, rules should always be as simple as possible. The "as possible" part is key, though - they need to be complicated enough to do the job.
Wikipedia's rules are _way_ too complicated: the only rules there that I have ever fully read through, in nearly two years, have been V, N, and NOR. Who's going to spend a day reading all of Wikipedia policy pages, which are contradictory in places? If they aren't, then the policies are practically purposeless; if they are, then we're creating a bureuacracy by making people have to worry about procedure.
People read the policies that apply to them. If you just want to write articles, V, N and NOR are probably enough (actually, you should read NPOV too). If you want to be involved in the deletion process, you need to read the deletion policy. If you want to be involved in vandal cleanup, you'll need to read the blocking policy. If you want to edit articles about living people, you'll need to read BLP. Not everyone needs to know every policy, that's the great thing about a wiki, each person can choose what they want to do and ignore the rest. However, the policies do need to be there for those that are doing relevant work.
People say, "Abide by the spirit of the policies, not the letter," but in this case why not make policies simple? If policies have a "spirit", so to speak, why can they not be contained in three pages instead of 50?
For the most part, following the spirit of the policies works, but sometimes people disagree on exactly what that means and it becomes necessary to have a more precise policy rather than having an edit war each time (we just have one edit war on the policy page! ;)).
Your constables will unilaterally delete articles they think don't fit the acceptability policy? In that case, you will certainly need a policy for arbitrating disputes!
Articles which obviously fail to fit the acceptability policy will be deletable on sight by any constable.
You'll eventually find it necessary to define "obviously", because people will disagree on it. That will give you CSD.
When constables receive a report about a potentially violating article and are unsure about whether or not it meets the acceptability policy, they will bring up the issue in some public venue for, say, 24 hours and invite community input and comments from other constables, then "follow the consensus".
And that would be AFD.
The existing Wikipedia policies could probably be trimmed and rewritten to be easier to read - that's what happens when policies are built up over time, they end up getting a little convoluted - but they are needed.
If you decide to go ahead with your project, then best of luck to you, and let us know how it turns out.