Vader wasn't Luke's father!

Think about it.  Annakin was Luke's biological father, but he hadn't become Darth Vader until after Padme had become pregnant.  He really didn't complete his transformation until Palpatine lied about Padme's death.  Sure, he was on the road to becoming evil, but I don't think he committed any crimes until after consummation.  He was just a whiny little 「female dog」 like most teenagers who feel everyone is out to deprive them of their freedom when in actuality are being guided in becoming good members of society.  At best Darth Vader was unknowingly a deadbeat dad: Never calling and never paying child support.  Luke only has a few chromosomes in common with Vader, as well as, some midichlorians(ha).  Of course some may argue that character traits are hereditary.  To some extent, that could be true but environment can also have a tremendous effect on psychological growth.  Uncle Owen was more of a father during Luke's formative years which shows in his naive way he sees the world outside the farm, as well as his fortitude in resisting the dark side and he matures with the help of surrogate fathers Ben Kenobi and Han Solo.  Darth Vader didn't become one of the most powerful, feared Sith in the galaxy because of his DNA.  He was manipulated by Palpatine.  Had he been trained by Yoda, he would've been a Jedi.  Palpatine may have twisted Annakin's mind while he was courting Padme, but he didn't change anything that could have been passed to Luke.

Just though I'd get this out.