Thanks for the info.

Michael,

Of course their's no harm in disavowing domains you're talking about (and not much time involved with doing it) but technically, those links are pointing to resources that doesn't exist and I've not heard of anyone who says they've been hurt by links pointing to non-existing resources on their domain. In fact, before we had the disavow tool, changing the url of a page with bad back links was a method used to try to avoid penalties.

Coraltoes,

There isn't any question about whether or not you can go straight to the disavow tool as a first step in cleaning up bad links, as Matt Cutts confirms here.  Exactly what the difference is between doing that and first communicating to all spammy link webmasters so that you have that file to include with your reinclusion request isn't so clear cut.

I suspect that you're not going to find anything else but you could go straight to google and use the link:www.domain.com  search operator to see what Google shows as back links.  That search won't show you everything but should give you an idea if there's more to the picture than what's showing up in those services.

That might be splitting hairs but if I were to choose, I'd point them at which ever had the stiffest competition--if that were the parent, I'd point the sub pages back to it; if one of the sub pages has the toughest go of it, I'd consider daisy chaining them.  Some of the value of that linking would probably depend on how evenly PR is spread between the pages, the page's locations in the site architecture, where the the links are located on the page, and whether such linking helps or hurts the conversion process, so ultimately, the desired value of such sculpting may be hard to realize.

What others have said:

• http://moz.com/community/q/pagerank-sculpting-best-practices-for-e-commerce-websites
• http://moz.com/blog/internal-linking-strategies-for-2012-and-beyond
• http://moz.com/community/q/page-rank-sculpting

It feels like you're paying to much attention to the grains of sand and not enough attention to the beach. Think at scale--do you really want to be editing everyone's comments for ever and ever?  How would your audience think about that? If you're audience is prone to misspelings and grammer errors (and whose isn't) so be it.  One comment is worth a few errors and google's not going to ding you for that.

Instead, think about how you can get more people who are going to make those errors to your site. Don't knock your audience if they're engaging with your content.

Yes, I read that too.  I'm sure you noticed the part about

"Content Rich Sites Get More Links

People feel content is so valuable that they are willing to link to in-depth content more than they are willing to link to content that is short."

Don't confuse google liking links with google liking content.  Google likes links--the content...not as big of a big deal (for google).

Don't think about Google "counting" the words on your page--it doesn't really care about how many words it contains. The thing about words is that when used well, they can give others a reason to comment or share or like it--and shares and comments beget more shares and comments.  A six word page with 50 comments is a whole lot better than a 2000 word page with none.  In answer to your question, the comments on a page do count towards to the pages's content but the fact that the page has visitor profiles that have commented on it is where the real value is.