I see nothing to really disagree with on your points.
I would remark that the reasons why I think the incumbent under 50% rule has been ignored more of late is because of the great amount of data that's come in over the past few years that shown that since the early 1990s, the trend has been towards undecideds breaking close to even between incumbent and challenger, as opposed to years prior to that period.
Oh, and about the Keystone Poll, it appears to be your standard uni poll. Strangely enough, its results have favored the Republican in comparison to other polls this year, but in 2004, its results skewed Democratic compared to other polls and the final result. The final result was Kerry +5. Just some food for thought. I just usually consider this to be your "crappy uni poll" bias.
Oh, among the news items, I thought you might like to know for your list that in FL-16, the Republicans will be allowed to put signs up at polling places saying "a vote for Negron means Foley". Only the Secretary of State is not allowed to. Apparently, Democrats are not appealing the decision either.
http://blogs.tampabay.com/buzz/2006/10/signs_going_up.html
With regard to the Keystone Poll, when I noticed that it clearly favored the GOP this year by comparison to other polls I went back to look at 2004 and also noticed that in that cycle it slightly favored Dems. I don't really know what to make of that, except to speculate that perhaps they overcompensated somehow in their methodology. Who knows? In general, I've not much worried about it and simply averaged in the Keystone Poll with all the rest when assessing the various contests, but with a relative dearth of polling in PA-08, and with the Keystone Poll at some variance to the latest CW on that one, I have to make an executive decision to minimize its influence on my rating. :)
With regard to FL-16 I've already been rating that one below 'consensus' and with the presumption that most voters who want to vote for Negron will know that a vote for Foley is a vote for Negron. The problem, as I've stated previously, is that I think FL-16 would be a Toss Up even if it were just a 'normal' open seat contest. Another way to look at it is that FL-16 was 1.8% less GOP than FL-13 in 2004, and 1.4% less GOP in 2000. If the open Harris seat can be a Toss Up then certainly an open Foley seat could've been so. But again, I have not leaped to the conclusion that FL-16 is a sure loss which is why I have it rated last in the Lean Dem seats.
With regard to the 50% rule, that's a controversy I'd just as soon avoid! I'll simply add that if there's any election where it should be applicable it is this year's prospective 'wave' election, so if there's any merit to it I think we'll get a clear sense of that once the election results are analyzed. That takes us back to the $1,000,000 question of whether this year is a 'normal' election or a 'wave' election. We'll certainly find out soon enough!