He didn't get the benefit of playing in the 80's or retiring at age 30 like the people ahead of him in the "goals per game" department

But he has the benefit of modern day training, science, nutrition, and other advancements that allows all players to play at a higher level later into their careers.

hat tricks is a really weird thing to include shootout goals definitely doesn't mean shit

They're goal stats in the NHL. Not crucial, but would probably be used in his favor he is was #1 in those stats.

Ovechkin has already scored more goals than Gretzky after the age of 30 and he still has 4-5 years left assuming a normal career (I assume he will play to 41/42 or until he has the record)

See my first point.