Is there a way i can tell a user who is having Adobe DC Pro is using the features that comes with it ( Deleting Pages, Combining files, Creating pdf) or just using it as normal Acrobat Reader
I'm pretty sure Adobe do not have any way to do this (It would be a hard sell in the planning meeting).
No, there is no way to find this out. The hard way would be to install Acrobat Reader DC instead of Acrobat Pro DC. If they don't complain, they do not use editing features.
Just to say: after this, you will be very unpopular in your company, except if you save a lot of cash. Then the CFO will love you.
Of course there isn't - what actually streamline and downgrade your licenses? Adobe would rather you have zero idea so you keep buying more licenses. Frankly a cruddy business model and somewhat dishonest.