Your loop looks fine. but I see no mention of fittings in your OP (unless I'm blind)
Try to get some angle fittings for a couple of tight bends in your loop, like the tube going from your bottom rad to your GPU, and from your res to...
I know that feel bro. Took a gamble with an MSI motherboard and got it with a dead ram slot.
No worries though. Dust yourself off, RMA that sucker and get yourself a fresh PSU. You'll be laughing about it soon enough!