Can you clarify the model? I'm not familiar with the 55UK65 and searches don't bring up results. Bear in mind that since you admit to not actually viewing any 4K content on your 4K TV, you're blowing up (stretching out) your PS4 image by 4x. That is obviously going to lead to blurring.

This IPS display seems to be a cheap ripoff of 4k and it doesn't even come close to matching how good my old plasma was for picture quality and refresh rate.
I'm not trying to be rude, but I don't understand what this means.
Refresh rate is just going to be a matter of personal preference. Your PS4 can only do 60hz and you generally want to turn off any TV settings that try to increase the refresh rate, as it negatively affects video quality in pretty much everything except sports (and even that's debatable).
At the end of the day, if you hate it, return it and get something better. I'm not sure where your model sits in the lineup, but LG is on par with Sony IMO.