In my view the new Usage analytics is more true than the old 2010 version of Web Analytics. Wikipedia says the following on Web analytics:
Web analytics is the measurement, collection, analysis and reporting of internet data for purposes of understanding and optimizing web usage.
And looking at the section on-site web analytics - definitions this was hard to come by in 2010 version. So what has changed?
Web Analytics in SharePoint Server 2010
Description: Web Analytics in SharePoint Server 2010 has been discontinued and is not available in SharePoint 2013. Analytics processing for SharePoint 2013 is now a component of the Search service.
What happens to Web Analytics after upgrade:
The Web Analytics Service is not upgraded to the Analytics Processing Component in SharePoint 2013. When you upgrade to SharePoint 2013, the databases that contain the data from Web Analytics in SharePoint Server 2010 are not removed. These databases are not used by or maintained by the Analytics Processing Component in SharePoint 2013. This means that documents on sites in SharePoint Server 2010 that are upgraded will show a hit count of 0.
Reference: Changes from SharePoint 2010 to SharePoint 2013
So the answer is yes, the old 2010 version on Web Analytics is gone. However - there is a new one available:
The different types of analyses
The Analytics Processing Component runs two main types of analyses: Search analytics and Usage analytics. Search analytics analyzes content in the search index, and usage analytics analyzes the user actions.
- Search analytics analyzes content that is being crawled and added to the search index.
- Usage analytics analyzes user actions, or usage events, such as clicks or viewed items, on the SharePoint site.
The usage analytics is very interesting, and in my view much better than the 2010 version:
Usage analytics is a set of analyses that receive information about user actions, or usage events, such as clicks or viewed items, on the SharePoint site. Usage analytics combines this information with information about crawled content from the Search analyses, and processes the information. Information about recommendations and usage events is added to the search index. Statistics on the different usage events is added to the search index and sent to the Analytics reporting database.
Reference: Overview of analytics processing in SharePoint Server 2013
b) No, probably more true in 2013
c) Upgrade is not possible