a) we potentially loose the opportunity to periodically drip other helpful info over time as we are not requiring name/email for this content. correct?

I think that you are giving up a FLOOD to collect a drip.

My experience has been that I get a LOT more traffic from the SERPs than I can get by collecting emails.

If you publish awesome stuff you can still collect emails... "Sign up for free updates by email".

If we do publish without "gate" then does it make a difference if this page with pdf is part of main/sub navigation or if we exclude it from that and make if available from pages within site?

I would not publish on pdf because they do not perform as well as html pages in the SERPs and they are harder to monetize.

Instead of excluding this from your navigation.. I would be shouting about it on my homepage and every relevant page of my site.  Drive as many people into it as you can.

**Does how far a page is from main navigation make a difference in relevance/importance from SEO Point of view? **

Yes.  Pages in your main navigation get more linkjuice and often rank better than if they had just one or two links into them.

I would be monetizing this content with ads.  They can be adsense, another network, or they can be house ads promoting your own products.

Getting content from some clients is like pulling molars from a stubborn mule.

A long time ago I used to have clients and after experiencing this problem I decided to start writing content and placing it on my own site.   After doing that for about 15 years, I have a lot of content that brings in a lot of traffic and I am far better off and enjoying myself a lot more than if I were still doing dental work on mules.

Have you thought about doing this?  Content producers are the most valuable people on the web (far more valuable than SEOs    And, if they know a little bit about making a website, doing a little SEO, and maybe a little about marketing they can make all of the money that their content produces year-over-year-over-year-over-year... etc..  you get it.... instead of selling it to mules for a one-time fee.

I really like visibility metrics because they are a single number that summarizes my competitive standing for a large number of keywords.

Are visibility metrics skewed?  Absolutely.  They are skewed because we select the keywords - the boundaries of comparison.

If we pick a large number of keywords that are representative of the industry area in which we compete, then that might not be extremely skewed.  However, since we define the basket of keywords ourselves, then we skew the metric in proportion to the keywords that we include that are specialties of our business.

I think that you should monitor the branded keywords of your business.  Knowing what's happening there can tip you off to health problems of your own website or people who might be infringing upon your intellectual property.

Let's say you start all of these new websites.  You spend a little work on this one, a little work on that one, a little work here....  then when your customers want to review you some will go to this site, some will go to that site, some will go to another site...

What do you have after that?  A collection of hotdog stands.  Nothing impressive.  You have a bunch of websites that are not much different from your weakest competitor who didn't work very hard.

When you enter competition in the SERPs you enter a melee.  You are being attacked from the front, side, behind, above and below.  The best way to win is to go in like a Rambo and start kicking ass.  If you go in without working hard, you lose.  If you go in with a bunch of hotdog stands you lose a bunch of times.

So, if I was you, I would focus all of my efforts on one website.  EmpireElec has a long way to go.  Put good informative useful content on there for each of your service activities.  What to do before you call the electrician for lots of your most common situations.  Be generous, inform people, save them money, weave yourself a huge white hat.  No time to do that? Then buy adwords, use the YellowPages.

About those domains... I would allow them to expire and buy beer with the savings.   You have one domain.  If you don't have the time or the engergy to make it kickass you are not going to do it with a dozen of them.

One of the "benefits" they cited was that they submit your information to local search/citation sites once a month, to keep it up-to-date.

I was on the phone with them recently and they started offering this... and I am thinking... "OMG... Please!  NOOO!    Then they told me the price and I was relieved that they were not going to do it for my site.

Does anyone still do this, or is NS just trying to make their product sound good?

Now I wonder how much they know about domain registration and hosting. 

To become visible in the SERPs, and to make money from those rankings, requires a lot of work.   If you split your time between multiple sites a lot more time will be required to bring any of your sites into money-making rankings.

So, until you have a site that is dominant in its SERPs, the best use of your time is probably to spend all of your energy and resources into a single site.

Once you have a site that is dominant in your niche, you can then afford a second site - and use the original site to give it a few links and get it ranking.

For a general answer... I have zero concerns about two (or even three) links to the same URL on a single page of my website.  I place links when it makes editorial sense and when it  is helpful to my visitors.

Although I have not heard any specific information about how google handles duplicate links on a page I doubt that they find a problem with it.  Why should they?  In my opinion, linking to the same URL two or three times on a page can be a signal of its importance.