I only just once used a Rem just to see if it  actually worked. Now I clean them out of folders just so I have less stuff to wade through.  I just inject another character pose on top of the current one if I change my mind. I don't see why you need to actually remove one first when you can just to swap it to another.
The only time I would find a Rem pose useful is if I'm mixing a purchased character into a custom morphed character and it doesn't work well. That's not something that many people do I would imagine... and for immediate disasters like that there is always an 'undo'.

As for hiding things I personally do find the Hierarchy editor faster to access than surfing through my Library folders to the relevant one.  Also because the Hierarchy Editor responds faster than a pose file does on my set up... there is always that little lag Poser seems to do before actually applying the pose.  Irritating if i want to hide a few things at a time.
 

" Try and be nice to people, avoid eating fat, read a good book every now and then, get some walking in, and try and live together in peace and harmony with people of all creeds and nations."
-Monty Python