To play the dvd on the hard drive with VLC, navigate to the Video_TS folder, then right click on it. You should get a list of options, including play with VLC.
We do not recommend Memorex DL media. It is very problematic in most burners. If you want to use double layer blank media, only use Verbatim brand.
Your burned dvd may not be playable in anything using Memorex DL. You'll just have to test it in a variety of players.