You're making this way to complicated. If you want to bypass the heater core, then just remove the 2 lines from the heater core and connect them together.
https://www.oreillyauto.com/detail/b...onnector&pos=5
Done.
FYI the driver side nipple (on the water pump) goes to the heater core. The one on the passenger side as you mentioned, goes up to the intake manifold.
The heater core returns to the manifold.
My thinking is the since the water pump is circulating to the heater core constantly, it probably should not be blocked off from doing so. With that in mind, simply making a loop could never hurt. Where as not doing so is a question. So if you are in a vehicle that does not have a heater core, Then the nipple on the driver side of the pump will hook up to the passenger side of the intake manifold.