As far as I know you can, as long as the PS4 is set as your main console, I used to do it from a hotel every so often. Quality drops a bit more depending on connection speed of course. I made my brother's PS4 the main console on my account to share my games with him and it doesn't work anymore...
Grabbed an (A) PS4 for $226. This was the description:
Condition: Used - Acceptable - Downloadable content (DLC) or codes for online play may require additional purchase. Item will come repackaged. Cosmetic imperfection(s) 1" or bigger on front of item. Small (less than 1/4" x 1/4") cosmetic...
He's just trolling. Block him and move on.
On topic: there's a minor restock, over a hundred items, but I honestly can't tell what they've added. They really need to fix these listings.