<p>All of the discussion reminds me of bureaucrats aiming to impugn a strict set of rules to a diverse set of circumstances. I'm skeptical such a list of rules can be derived or agreed upon. To hijack your question (sorry) I'd prefer to focus on actionable steps the community can take to better resolve such disagreements. I'll propose two;</p>

<ul>
<li>A sizable proportion of such disagreements are over ill-defined questions (oft by new users). We can <em>encourage</em> reviewers to be less hasty in voting for migration when such questions occur and encourage other actions such as editing (which can be more easily reversed). </li>
<li>A forum for discussion on borderline questions (much like the one Gavin suggests the R community on stackoverflow has). Whuber states <a href="https://stats.meta.stackexchange.com/a/1771/1036">we migrate on average 2 questions a day</a>; this is few enough discussion can be taken on an individual question basis when disagreements arise. This can be accommodated via chat.</li>
</ul>

<p>Of course as best we can do is encourage such behavior (we can't force individual action). The biggest impediment at this stage IMO is getting adoption of the chat system. Fingers crossed, we may have enough community participation at this point (if we prod people enough) to establish regular participation. </p>

<p>I just don't think adding to the already long list of guidelines has any utility to the site. I'm skeptical the FAQ is an effective vehicle to encourage behavior for either newcomers (asking questions) or regular users (the ones voting to migrate).</p>
