1)Well excalibur was exceedingly phallic. Only the true king could pull or push it from the rock and was delivered up right(I think) by the Lady of the lake.

2)The affair between Lancelot and Guinevere...

3)His sister Morgana was sure more patient ,considerate and 'hand on'...not to mention she had been experimenting with mandrake since she was a kid

4)According to one account,excalibur was lost. Arthur fell ill, then quest for the holy grail.