I do understand his check though.

With what hand that doesnt beat him would i call a bet with?

Only for example A7 or A8 with the Ace of Spades.

If I had 2 pair of a set on the flop i wouldn't have just called on the flop twice. I would have bet/raised. Also when flopping a lower flush I would have bet/raised.

Another legimit reason for betting on the river with the Q [img]/images/graemlins/spade.gif[/img] and 6 [img]/images/graemlins/spade.gif[/img] is that you don't want a showdown, because that will give information to the other players.