I'd agree but probably feel a bit more strongly about it - post-Panda, these kinds of pages can definitely cause you harm (depending on the scope). If you're not linking to them and they're off on a sub-domain, they may not be creating any practical issues, but it's still better to prevent problems. META NOINDEX probably is a good bet here for prevention.

The new Difficulty score gets pretty aggressively scaled, because we found that the distribution of PA/DA was bunching up a bit, and fell almost entirely in the 25-85 range (looking across an entire SERP). So, a 25 gets scaled down to nearly zero, to give the new metric more granularity.

It looks like the CTR-adjusted PA for "Naturmode" on Google.de (for example) is right around 26, so it may be that the PAs have gone down a bit over time as well. Even by the non-weighted metric, I'd expect that to be a solid 10 points lower than the old difficulty score.

We're going to dig in and try to find out if the rescaling is too aggressive, once we have more data from real-world KWE usage. In general, though, you're going to see a bigger range of difficulty scores with the new metric. It's pretty tough to meaningfully compare the old and new scores.

If you had a very large number of internal links, that could dilute your authority in some cases, but some of that should be factored into MozRank. Having too few internal links shouldn't be an issue, unless you were artificially restricting your internal PageRank flow somehow.

This is almost impossible to diagnose without seeing the specific case, but keep in mind that none of our metrics really account for any filtering or devaluation Google might do. So, if they felt some of your links were low quality, or there was a bad pattern to them (too much reliance on one type of link, such as footer links from clients), or you were hit for excessive exact-match anchor text, etc., that wouldn't necessarily show up in our metrics.

The other issue would be any sort of technical issue with the page or even an on-page problem (a low ratio of crawlable text, too many ads, bad targeting, etc.).

Our new Site Crawl can provide a full audit of your site (whether or not pages have issues) with information like crawl depth and Page Authority, but both tools have pros and cons. We use a cloud-based crawler (pardon the term) and Screaming Frog runs on your own machine -- even this has pros and cons, depending on your use-case. We now allow on-demand recrawls for Medium Tier on up. Screaming Frog has more customization, if you're looking for specific patterns and generally offers more raw data, I'd say. Our new Site Crawl is a bit more accessible to most users and helps provide insights, but doesn't have a lot of customization options right now.

If you've got a Moz plan that covers the size of your full site, then either Moz Site Crawl or Screaming Frog should be able to help you audit your full list of pages prior to an HTTP-->HTTPS migration.

I'll give you that - it's true that the result highlighting alone doesn't prove Google is viewing "shop ipad" as 2 words for ranking purposes. The tough part is separating out why these pages rank - I've seen plenty of URLs with underscores rank perfectly well, but there's no way to prove it isn't on other factors.

I think we're generally agreeing, though, that the potential risks probably outweigh what would probably be a very small boost at best. I'm also a little hesitant on having some pages with dashes and some with underscores, but that's probably just the UX side of me - it feels messy.

I hate to say it, but I'm with Marty. There's just no way to tell, and it's completely dependent on the editor(s) for your niche. Recently, I'm seeing many cases where people get a DMOZ listing and it's so deep in the site that the page isn't even indexed - so they wait months for this "great" link that then passes no link-juice at all. File a good submission and get on with life - that's all you can do, unless you know an editor personally.