What to do on river when passive villain wakes up?

[Tempel]

I've got a situation that im unsure of what the best thing to do is, i need reasoning above straight answers...

The Villain in this situation is bad, station, playing ~60/8 or somethn.
Effective stacks is given on river split. But atleast 100bb ($100)

Preflop villain openlimps ($1) from MP, You raise it up ($5) with 8 [img]/images/graemlins/club.gif[/img] 8 [img]/images/graemlins/spade.gif[/img] from the button, all folds but villain, who calls.

So far, you are not surprised at all by his play. Not his openlimp, or his call.

Pot is $13
Flop comes 4 [img]/images/graemlins/spade.gif[/img] 8 [img]/images/graemlins/heart.gif[/img] K [img]/images/graemlins/heart.gif[/img]

Villain checks, but you know he's a station so you bet $11, Villain calls.
- What range can we put villain on here?

Turn 2 [img]/images/graemlins/club.gif[/img], does nothing. Pot is now $35.

Villain checks again, you're going $28, He calls.
- Does the range were putting him on on flop changes here?

Pot is now $91, and the river brings T [img]/images/graemlins/heart.gif[/img]..
Villain wakes up and openpushes...

a) 100bb's effective stacks (push is $56, giving us 3:1)
b) 140bb's effective stacks (push is $96, giving us 2:1)

a & b) Why do we do what?

x) Is this always a flush or can it be something else from this villain?

Im sure this is standard for you, but id like som reasoning behind ur answers..