Do I have to completely HIPP at least two documents to get full credit for points or can I only do one thing from HIPP on both the two documents of my choosing?
You don’t have to fully HIPP a document, but you can to create a buffer if needed.
Is there a requirement of how many elements of HIPP in the documents? (like 2 out of the 4 HIPP tools)?
You must use at least one
I would also recommend using either H or IPP all together, as those three are fairly tied together.