Caveat: this is checked via Wikipedia, so add appropriate levels of skepticism. It sounds right to me, though.
PoW is given to the heir apparent, only; that is, one who cannot be "trumped" by another birth. The eldest son is, naturally, the heir apparent under a male primogeniture system.
Q1: the title is contingent on his being the heir *in a way which the elder son is*. Q2: I think Edgar would actually be king at that point, since the senior line is not extinguished; there would be no Prince of Wales as the heir presumptive (Bernard) can be pushed lower in the succession. Q3: See above; Edgar is king, Bernard is heir presumptive, nobody's the PoW. Q4: He's the king. Q5: not sure on these.
no subject
PoW is given to the heir apparent, only; that is, one who cannot be "trumped" by another birth. The eldest son is, naturally, the heir apparent under a male primogeniture system.
Q1: the title is contingent on his being the heir *in a way which the elder son is*.
Q2: I think Edgar would actually be king at that point, since the senior line is not extinguished; there would be no Prince of Wales as the heir presumptive (Bernard) can be pushed lower in the succession.
Q3: See above; Edgar is king, Bernard is heir presumptive, nobody's the PoW.
Q4: He's the king.
Q5: not sure on these.