Made a lot of progress today. We dropped the charge down to 26 oz, and things are WAAAY better. 90F, and even after extended idling, the high side was around 280-290 (still a bit higher than I'd like, but certainly better than 350-375). The HPCO no longer trips, even with about 1,500-1,800 RPM. The low side was 44-45. With the fan on max, and going down the road, I saw the vent temp dipping into the 46-48 degree range. Turning the fan speed down one notch resulted in 42 degree temps, and the clutch started to cycle. Once I finished my test loop, I popped the hood, and the whole accumulator was sweating, along with about 1 foot of rubber hose on the suction line off the accumulator. I think the charge is pretty much right on now. I might play with dropping the low pressure cut out just 1 or 2 psi to get that last little bit of cooling, being careful not to ice the evaporator, of course, but overall, MUCH happier with the system! I'm blown away by how small the charge is. I guess that PF condenser compared to the giant factory dual tube serpentine, and my shorter than factory hoses made quite a difference in system volume.
Thanks again for all the help and input!