The inclusion of updates goes by time, not by the major version numbers. Please check your update period in the About dialog in your current version 6. If it has not expired, you are can update without re-purchasing to any version 7.x released within your update period:
I'm unsure what it's called, but in v6 the graph would fade when I moused over it. Having the graph there all the time is inconvenient as I have to keep moving it to see things behind. Is this still operational and how do I set it up in v7?
The fade feature is not available in version 7 due to cross-platform limitations. If you absolutely need the graph to fade away when mouse is over it, you will need to downgrade to version 6.
However, if you don't require the fading per se, but rather wish to be able to quickly show and hide the graph, there is a simple solution in v7: set up a global hotkey to show/hide the graph any time you want.