Emre,
I've rebased and tested your proposed patch. It seems fine and sensible to me.
I have only one thing to note: as this patch doesn't disable <^ and >^ operator for boxes the existing state of documentation seem consistent to me:
select '((0,0),(1,1))'::box <<| '((0,1),(1,2))'::box;
----------
f
select '((0,0),(1,1))'::box <^ '((0,1),(1,2))'::box;
----------
t
So I've only reverted the changes in the documentation on geometric functions in your patch.
PFA v3 of your patch. I'd mark it ready to commit if you agree.
Thank you!