How have the core SEO attributes of page tagging evolved and what at the projected changes going forward?
Yes, the SEO attributes of page tagging have evolved, but many of these core SEO tags still apply— the page title, meta description, image alt attributes, hyperlink titles, header (Hx) tags, meta robots, and canonical tags.  Structured data markup tags continue to gain importance in SEO. Any new schema markup tags will be critical.

Have the engines evolved what they value and how they evaluate Titles, headings and tags
They are still valuable and should represent the page, and ideally, what a customer would find important. Social sites often pick up the Title tag to determine what to display if the page is shared.
 What role is “structured data” and its variants(e.g. Microdata and Schema.org) playing in SEO?

Search engines use structured data to generate rich snippets, small pieces of information that will then appear in search results. Structured data makes it easier for web crawlers to determine company basics, such as NAP (name, address, place) data. Localization and personalization of search results make semantic SEO and structured data increasingly important. Mobile is driving the semantic revolution. As users transition from PC-based searches to mobile searches, structured data and SEO, rather than keywords, will have a greater impact on search engine results.

In your opinion, how important is the use of structured data going to be and how will it evolve?
Structured data will continue to gain ground in the SEO world as highly structured information makes it easier for search engines to organize and display rich snippets in search results. Google will start using schema markup both as a site quality and richness indicator (i.e., affecting rankings), and for creating carousel-like results for certain searches, with Knowledge Graph-like summary data on each result in the list.

Will sites that “help” the search engines with structured data be scored more favorably?

We think so. A business’ ability to effectively use structured data should increasingly dictate whether their website will favorably appear in SERP.

How does Google view the relationship between content and structured data?

Many websites are generated from data that is stored in databases; when this data is formatted into HTML code, it can be difficult for web crawlers to effectively interpret. Structured data is on-page markup that enables search engines to better understand the information currently on your business’s web page, and wil use this information to improve your business’s search results listing.

To what degree does the use of structured and Schema tagged data change long standing “duplicate” content rules. For example, if some structured data provided by a listings provider (and its syndication partners), mostly agrees with the structured data on an SMB site how do the engines evaluate this?
No, we don’t think search engines will consider them as duplicate content.

Who does the Google view as the authoritative source of SMB specific structured data?
Schema.org

How will service providers “game” the structured data movement?
Google has already started sending penalty messages to sites using spammy tags in the Google search console.  Just like Google depreciated authorship and publisher tags, they too will start pulling down some of these schema tags and keep on introducing new ones.

What tagging strategies have you developed to specifically enhance SEO, and especially Local SEO, for your clients
We make use of the below tags to enhance Local SEO,

–   Title & Meta Description tag
–   Header (Hx) tags
–   Schema Markup for Local business
–   Image Alt & hyperlink tags
–   Canonical tags

Are geo-modifiers still required?
Yes