For the diode check, could it flag if a diode is forward biased?A
Yes, in the "Power Connections" checking, if diodes are turned on (option), under "Appropriate Use", they will be checked for forward-bias.
Note that there can an impact if some power supplies are defined with min/max range. That is, possible forward-bias diode will be checked for the worst combination of min/max on each side, to find any possibility of forward bias. (Just an addition to the normal checking of rails with single values - Requires no special preparation)