My client will not let me design a product before making it live.... "Make it live so I can see it, then I will fuck about with the design (pixel by pixel) and THEN I will work out what the product should actually do."
WTF?!
Oh and when I do insist on designing before building, they insist on me doing that in POWERPOINT..!!
Why am I still doing this fucking job?

Just do what he says bro. Its better for you. Because the client will pay you and the client will then pay you again for redesigning. Pay again for changing pixel by pixel. Unless youre fucking dumb as shit and do allat for free you're actually overcharging the client, exploiting him, MILKING him like a cow to his last drop of penny, abusing him BUT he absolutely 100% deserves it because hes fucking dumb. As my rude violent and arrogant math teacher told me: "who gives a fuck about you if you're fucking stupid". Hes right. Nobody. And if you let the client know about the recommended approach, and additional costs beforehand, and he still insists to be dumb as fuck, let him be dumb as fuck! More money for you. Nobody gives a shit about stupid people

You could always set up a second domain for demo purposes. That way their existing site isn't replaced and they still get to see it in real life.

As for using PowerPoint for design. I refuse to believe that. That cannot possibly be something a human would request of another human.

"make it live so i can see it before i design it" is shit i'd have to do when designing something for a personal project. it's a nightmare to meet *my own* needs that way, much less others' needs, but some people learn best when fucking around to find out.

Things like "make it live so i can see it before i design it" would be required of me when working on a personal project's design. It's so difficult to satisfy *my own* wants that way, let alone anyone else's. However, for some, the best way to learn is to screw around until they discover it works.