Enable comments as default for Reader

I use Acrobat Reader thoughout the day to comment on student scripts. Each time a document is opened I have to click in 3 separated parts of the screen to enable comments.

How do I set commenting as the default way to open and view a PDF document?

I used to be able to do this, but now I waste a considerable part of my angst on enabling commenting many times a day.

Or can you suggest an alternative program that does provide such a feature, if Reader has deleted it?