If you already have the $9.99 Basic plan, you can keep it.
I've been putting off having a local copy of the series and movies I watch because I still can access them quickly and cheaply enough in some streaming service, I think it's time to plan ramping up my selfhosted setup.
Yep! The Plus/Pro line is the good shit. The base models of WD drives are not great now, especially if you're going to set up a RAID array of some sort.