You may want to double check the oil lines on that bypass filter. There should be a restriction in the return line from the filter. You can check to see if the oil pressure rises by blocking off the filter lines and driving it.
However, I would be willing to bet that this snake oil coolant stuff that you have in your radiator isn't as good as you think it is at heat transfer. I would go back to 50/50 antifreeze/water and change it every year, and put the thermostat back in, and I bet it will work a lot better.
