Lots of questions here, I will simply point you to vipm.io from when you'll be able to get VIPM related info.
There are 4 'levels' of VIPM, free, community, pro and entreprise, see differences here https://www.vipm.io/download/
As far as I know VIPM is not a tool that will let you manage license subscription in your product, for this I think the best starting point is on NI forums : https://forums.ni.com/t5/Developer-Center-Resources/tkb-p/7307
As a side note, I think handling different types of licenses of your product is not an easy task, good luck with that!