#1 ePO 4.6.9 not supported [McAfee KnowledgeBase - ePolicy Orchestrator 4.6.9 Known Issues] you have to consider 5.1.2 or 5.3.1
#2 Yes, you have to upgrade Database first before upgrading ePO. This will be first thing you will be doing.
I would follow as below:
1. Follow KB66616
2. Install SQL express 2012 on new 2012 R2 server and then detach and attach the DB to new server and change the core/ config accordingly. [https://kc.mcafee.com/corporate/index?page=content&id=KB68427]
3. Now you can use Upgrade Compatibility Utility to migrate ePO from old server to new server.
Since the servers are having two different host names, the clients reporting to the old ePO 4.x server need to have a way to reach the new server. This can be done by changing your DNS records to have the clients trying to reach the old ePO 4.6 server to redirect to the newly installed 5.x server.
you can re-deploy the agents once EPO 5.x is installed.
Also check comments from few experienced users here : epo4.5 to epo5.3 [i.e. transferring client from old server to new server]
This is exactly the kind of answer I was looking for straight and to the point.
since some time not working on McAfeee ( specially not worked on Web Reporting)