There are a lot of things that can cause rings to go bad.
Too much back pressure
Leaking injectors diluting the oil, causing scuffing to the cylinder walls
Low oil or low oil pressure
Not changing the oil/filter
Are you the original owner?
As far as pulling the motor, well, I don't know. Clearly there is an oil consumption issue and that is not going to change.
What you don't want to do is mess up the cylinder walls so badly that you need to go 60 over on a first rebuild. At this point, if you pull it, you might get lucky and only need to hone the cylinders and and put in new pistons and rings. But, you wont know that until it's apart.
Bad news doesn't get better with time.
Gone, out doing soft recreational past time with overpowered boat!
ALABAMA'S #1 BANDWAGON FAN!! AND DOESN'T WANT TO WAIT UNTIL 2014 TO PLAY THE ONE AND DONE CREW!!!