I'm a bit late coming to this discussion, but I'll throw my two cents in.
It seems that we all generally agree on what the abstract requirements should be to access the Enclave:
1. "Good Behavior"
2. General Commitment to the site
The disagreement seems to arise about what objective standards correspond to these.
I think that requiring a warning level of 10% or lower adequately serves 1. I think that the permanent nature of smites and the nature of positive karma argues against a requirement for overall positive karma. Here's what I mean. Smites are permanent, but positive karma is not meant to represent good behavior, it represents particularly good posts (and other contributions). Unless mods become much more vigilant about recognizing each and every contribution, I think that an overall positive karma requirement is unfair to those who got smote in the past. We've discussed negative karma decay before, but that's a different topic.
The second general requirement that everyone seems to be arguing for is a sense that a member is not joining merely for the Enclave. I also believe that this is adequately served by a straight post requirement. I think that a post requirement of 250 posts (or whatever), shows that someone is serious about the rest of the site. They may not have made any great contributions, but they presumably haven't been spamming (or their warning level will be elevated and they will be denied access due to that). In short, I'm confident that someone wouldn't be able to spam their way to the requirement and avoid the notice of the mods. Additionally, it ensures that they are in the main part of the site for a while, learning the rules and good posting habits.
I also don't think that either general principle requires a minimum positive karma. The main reason is that, to put it simply, there are posts out there that probably deserve applauds, but don't have them. I know we have the flag-a-post function and the mods do do a good job, but it remains a subjective system. Additionally, it has always been claimed that karma did not make someone better than someone else, so I think it is not in that spirit to make distinctions about Enclave Access based on it.
If we wanted to do something like the new current system (post count or karma) I think that the idea of encouragement karma needs reexamined, or the limit should be more than +1. I admit that my first applaud was encouragement karma, but I didn't know what to think about it at the time. If people are getting into the Enclave on their point of encouragement, it is entirely possible that they will be exposed to it before they've internalized the generally high quality of posting that the site has elsewhere.
Anyway, those are my thoughts,
TB