I've experimented with - and pushed the limits - with rich snippets. When they do work, they were the single biggest factor in increasing CTR , I've ever used.
As you noted, the first thing and easiest would be to itemscope itemptype your business with the real estate agent classification and then add your address etc. all the basics. ( you can use your logo as a business image ). Maybe this helps in Local search, but it is difficult to tell. But it can't hurt and it is easy to do by simply wrapping the itemscope itemptype pointing to real estate sales agent in the HTML tag.
Now the following are just tactics
My next focus would be setting up the authorship verification so that I could get my picture in the SERPS.
Second, I would code my breadcrumbs - in the past I've found that the schema.org metadata doesn't work as well as the other formats. Download Yoasts Wordpress SEO plugin and look how he formats his breadcrumbs. His way works - you can mix types on a site without problems.
Since your homepage doesn't typically have breadcrumbs, make some, these will show up as a mini menu, remember that in the SERPs the breadrcrumbs will show from right to left - truncating the left side items first, put your your most important link at the left to always show up in the SERPs
Every site that I've wanted or didn't want shows breadcrumbs on almost every page.
Images and video objects seem right now at least to work just as well with sitemaps and descriptive alt and title content and I would not waste my time adding the schema info.
There are some others that work well still but perhaps not right for a real estate site.
Last but not least, I would not waste my time coding up the addresses etc for the MLS real estate listings as they are IMO just a mass of duplicate content across the web. Think about it, why would you trust a geo coordinates more than just a simple address?
I'd focus on the neighborhood landing pages - perhaps making them quasi blog posts so that I could get use of the authorship pic.
Then make the property pages templates more appealing, ones that t will convert by moving away from the standard MLS format.
The frustrating thing about schema.org and the other formats is that when they work one day and then they are gone the next. Your CTRs increase when they are working , but testing and coding takes time as they testing tool has bugs and information on the web and examples can be outdated or just plain wrong.
As for whether it helps with rankings, I'm not sure and my gut feeling is that right now they are not a highly rated signal in the algo if at all, but as I said before, the rich snippet portion if and when it shows up in the SERPs dramatically increases CRT
Lastly and most important, it is my opinion, that, based upon your post, you are granulating the process too much. Basically making it too complicated - as I believe John from Distilled pointed it out. This tendency to overcomplicated the scehma.org info is perhaps the reason this data is not a stronger signal yet nor been adopted widely.
As you stated, just keep the top level real estate sales agent as your top level, forget about the offerings, WebPage, SearchResultsPage, etc, next if you have a blog as part of your site add the authorship.
You can then focus on the itemproperties ie NAP and breadcrumbs, etc. Best to keep it simple for now.
If you need some up-to-date info about this check out John Mueller on Google + http://goo.gl/Ow7jI He always answers questions directly and has been a big help to me and others
