By the way, in regards to the length: have you considered chopping out that last little bit after the third SMWC coin, and actually making the last part the Roviclaw area (with a bit of an extension, I suppose)? Sure, you'd have to move that third SMWC coin, but if you make a giant Roviclaw section, it should be really easy to find a spot to hide it. I can still think of a couple of gimmicks that could be mixed in with it so that it doesn't feel too repetitive:
-Timing a P-Switch press so that you can pass through some used blocks (now coins) with the Roviclaw.
-Falling on a springboard, and using it to spring to a higher Roviclaw.
Those two ideas, at the very least, might help in drawing your level to a close.
(I think a little piece of me just wants to see more usage of the claw at the very end, so eh.)