So you're holding about 42#. For me, this would be ideal for a .600 spine arrow with a 100 grain point, although YMMV. You didn't say what length your .500 spine arrows were, but I would think a full length .500 spine arrow with one of the heavier points you mentioned would be the equivalent of my .600 spine arrow. However, carbon shafts are very sensitive to length, so if you have cut them back to 27” or 27.5” they might be too stiff regardless of the point weight you're using.
I assume you're a RH shooter? Since all your combinations are showing weak, and your nock is showing high (I assume you have tried many different nock positions and they all show high?) my guess is that you have either a false weak or a false high or both. This condition is the result of the arrow shaft recoiling off the strike plate or the arrow rest or both. A false weak or a false nock high could either be the result of using arrows that are too stiff or a problem with your shooting form.
Shooting form errors that can cause false weak or false nock high include torquing the string or bow or both, and failure to use adequate back tension to get the string elbow lined up behind the arrow. Too high or too low or inconsistent string elbow can also cause this condition. As can the use of arm muscles to draw the bow rather than back muscles.
A .600 spine arrow with a 100 grain point, or a .500 spine arrow with a 175 grain point, cut to 29”, and a nock point of 5/8”, can't be that far off, if you just want to shoot for a while and not worry about your form issues right away.