Scraping Mouse Over Generated Data
I've been building web scrapers for over 5 years, and I have to say that a web scraper is rarely "relatively straightforward" simply because of how idiosyncratic each website is. It usually takes a minimum of 10 hours per site to code your scraper if you know what you're doing. 

Whenever you have to interact with the page that you're scraping, I recommend Selenium. It's open source and works with most major languages, including Python, Java, and Scala. Moving a mouse around is possible, but I think in your case it might be easier to directly call the javascript that is triggered by the mouse movements. Your web scraper would iterate over all of the hoverable html elements and call the on-hover javascript on each element. However, the devil is in the details, and you're going to need to post a lot of questions on Stackoverflow and do a lot of Googling before you get to a final solution. 

I've heard that Google has an API for their maps capability. That might be a lot easier.