I can share some of what I do. I don’t want to sound too much like a commercial or for anyone to think I am trying to use someone else’s forum to solicit business.
As I see it, you are answering a direct question from me, which I asked here because I knew your reply would be interesting and informative for all readers, which turned out to be true. Thanks for all the time you put in to addressing my question Mike.

One quick question, which will probably only be useful to me. I don't have or want the Windows OS. Do any of the programs you reference run on the Web or Mac?

I'm going to skip over any philosophical type questions here, to avoid distractions. We can discuss issues like "unethical" and 'black hat" in another thread if anyone wishes to.

On to business...

My general impression is that most blogs use nofollow links in their comment sections these days. Is this your experience, and if yes, how does this factor in your calculations?

Ignoring all the wanna be search engines makes sense to me. I have high rankings for some keywords related to Google Adsense on Yahoo, which is fun to see, but the traffic is minimal.

I do not believe you will get slapped by Google for building links too fast.
I have no firm opinion here, and claim no special knowledge, but when launching some of my sites I've added thousands of links all at once from my own sites, and a friends site, and nothing bad seems to happen.

I always do everything behind proxies. No footprints.
I know what a proxie is, and why they are useful, but not which of the seemingly thousands of proxies are user friendly etc. Advice?

I build a lot of linkwheels with Web2.0 properties (Wordpress, Blogger, Vox, LiveJournal, Webs, YouTube, Vimeo, etc.).
Let's clarify this a bit. You create blogs on the free services you've listed above, and send most of your automated links to these blogs. And then you link from these throw away blogs to your real site. Did I explain that correctly?

You don’t care about the conversation on their blog.
Honestly, I wish this were true for me. One of my main problems is that I care about the conversations too much, and waste a lot of time in them, building other people's sites instead of my own. Like I'm, um, doing right now.

I create many different feeds that then get submitted and pinged with RSSBot (one of the best paid tools you will ever find).
Hmm, I need a little RSS 101 class. RSS is a weak area for me. A feed is a document a news reader can read? Where do you submit these? How does it help you? Anything you can share will be an education here.

However, backlinks, backlinks, backlinks is what it has been about for years. I don’t see that changing anytime soon.
That makes sense to me, and I would say from my own stupid experience, and reading webmaster forums for years, that not giving links adequate attention is perhaps the leading webmaster mistake.

On the flip side, the engines are going to have to address the challenge sophisticated automated link building systems present somehow.

This is a very well established pattern which goes back to the very beginnings of the SEO industry.

Clever results manipulating techniques work while they are new. Then the technique is popularized by tools and experts that make it easy for the masses. Then the engines have to respond, the technique is defeated, and the cycle begins again.

The SEO expert industry drives and thrives on this cycle, because it means that their customers have to come back to them again and again, to get the latest inside tools and tricks etc.

Trying to say, automated link building tools devalue the "voting system" that Google hopes to use to measure site quality, and so we can predict that eventually this link based voting system will have to be abandoned. I have no clue what it might be replaced with.

Before we get all moralistic about this, we should recall that Google is the biggest content scraper on the net. They don't ask our permission, they just scrape our sites with automated tools, and use our content to sell their ads. Sometimes Google provides value in return (web results) and sometimes they really don't (image searches).

In any case, they do whatever they want to do. As example, they are trying to scan every book ever printed in to their databases, and it's up to the publishers of these books to negotiate with Google about it. Google started scanning, before they started negotiating.

So, the philosophical situation is rather complicated.

Mike, if you don't know him already, I'd suggest you meet Charles Heflin. http://www.charlesheflin.com/
He has a membership site built around a highly automated social networking system, right up your alley. I was a member for awhile, and Charles seems like a good guy. He asked me to code his system, but I'm glad I didn't, as he wants to explore far beyond my abilities.

If nothing else, I think you would likely benefit from a one month subscription to see if what he has to offer is useful to you. I don't understand these issues well enough to know, but you would.