Q:

Etiquette for notifying personal contact on faculty search committee about applying for a position

My question has to do with the proper etiquette for notifying a personal contact on a faculty search committee that I am applying to.  The question is based on the perspective of U.S. institutions.  
Background:
I am a doctoral student about to go on the job market.  Several months ago at a conference, a colleague from my master's program introduced me to his boss, for whom he has worked for around 5 years. The boss, it should be noted, used to work at my current institution.  While I am not sure of the circumstances of his departure, it seems he is still friends with some of the professors in my department. Through our conversation, I found out that their department was going to hire several new faculty members sometime in early summer.  I went on their university's HR website about 3 weeks ago and saw the posting.  I reached out to my colleague to reintroduce me to his boss, so that I could ask the boss questions about the faculty search that he (the boss) may be able to answer, i.e. whether the position was "truly open" or if it was only posted as a formality (having been on the other side of the hiring table in my previous life, I knew that sometimes institutions already have an internal candidate, but they have to post the position as a legal requirement, particularly if it is a public institution).  The boss replied to my e-mail and told me that: 1.) the position was truly open, and more importantly, 2.) he is the chair of the search committee.  He also asked me whether I had already submitted my application (I have not).  I am in the process of replying to his e-mail, and would like advice on how I can maximize my connection without sounding desperate or annoying.
Questions:

Is it appropriate for me to tell him that I am putting my packet together and that I will let him know when I submit the application? 
Following (1), is it appropriate for me to ask him to be on the lookout for my application when/after I submit it?
Is it appropriate for me to ask follow-up questions about the person they are looking for, for example whether there are specific courses they're trying to develop within their department, whether there are research areas they're specifically looking for, etc. so then I can "tailor" my cover letter/teaching statement/research statement to what they need? 
Should I be taking advantage of the fact that the search committee chair is still friendly with several people on my dissertation committee by having them contact him?
The expected start date is sometime in late fall of this year, but the posting shows a closing date sometime in the summer next year.  Can I ask my contact when he expects to start reviewing the applications? 

A:

Is it appropriate for me to tell him that I am putting my packet together and that I will let him know when I submit the application?

You most definitely want to respond ASAP and let him know that you are in the process of applying. It is not necessary to follow up further and tell him when you have applied, but nor would a quick email saying something like "Just to let you know, I submitted my application on the HR system today" be out of place.

Following (1), is it appropriate for me to ask him to be on the lookout for my application when/after I submit it?

I would not use this terminology. Your communication with him is implying that he should keep a look out for your application. No reason to be blunt.

Is it appropriate for me to ask follow-up questions about the person they are looking for, for example whether there are specific courses they're trying to develop within their department, whether there are research areas they're specifically looking for, etc. so then I can "tailor" my cover letter/teaching statement/research statement to what they need?

One can always ask a search chair this, but as they are the search chair and do not personally know you, you should expect a non-informative answer. This is a much better question for your personal contact/friend. In your case since the search chair used to work at your current department, someone in your department (possibly your advisor) who knows the chair personally, could also reach out to the chair.

Should I be taking advantage of the fact that the search committee chair is still friendly with several people on my dissertation committee by having them contact him?

YES! YES! YES! I really cannot say YES enough. As awful as it sounds, this is how you get a job. You want to do this in a coordinated manner. You do not necessarily want every member of your department calling up the chair. You need to sit down with your advisor and discuss this search (but also all the searches you are applying for) and figure out your application strategy.

The expected start date is sometime in late fall of this year, but the posting shows a closing date sometime in the summer next year. Can I ask my contact when he expects to start reviewing the applications?

This falls into one of job postings that is confusing for applicants. Presumably, they want someone to start ASAP, but do not want to lose the position if they do not get a good applicant. They also could have screwed up the deadlines. This is something you could ask the chair. If the posting suggests a person to contact about questions, you could also ask them.

