Will slightly rich cause a problem?
Bad mileage, perhaps fouled plugs.
Less oxygen seems like it should be leaner
Correct
Clifford suggested #48 jets and 8.5 PV for the 235, which uses less air volume.
The WOT fuel volume from jet A vs. jet B is not the ratio of their areas, since the main only supplies the cruising (high vacuum) circuit. WOT fuel is also supplied by the PVCR which in your case is .038".
Remember:
1. Holley jet # is not the ID except by coincidence

2. the PV rating is not the size or area, only the vacuum point when it opens. All PV add the same fuel volume in the same carburetor.