Chamber of Secrets set 4730 assembly issues We recently obtained a secondhand set with no instructions that I identified to be "The Chamber of Secrets™ 4730". So we downloaded the Building instructions from Lego's website and started to build. But there were a few issues we were confused about as we built--and I was hoping some other lego expert builder might be able to clarify.


Step 3 on page 5 adds a 2x3 brick that hangs off the side of the board. What is this piece for? It seems kind of extraneous, and the best I could come up with was that maybe this was to attach the baseplate to another baseplate from the set?





Starting on page 16 through page 20, you build 3 towers. The instructions are incredibly vague about where these towers are attached and which orientation they should face. Page 61 is the only place I can see that even shows the towers attached to the buildings, but it only gives you a side view with how overly compressed the images are on the pdf, it's hard to see. Any 3d models of this? or photos of a different angle of the completed models?
Am I correct in thinking pages 62-66 is an alternate build? That isn't intended to be made at the same time as the previous pages? (I'm not missing a ton of pieces am I?) 
Hinges... The ones added on page 32 in step 17 of the skull-face wall. To what should they attach? They appear to, perhaps, be used to attach the skull-faced build to the two large builds? But where exactly?


It kind of looks like it ought to fit like this...but the 3x4 towers are in the way:



This was the only thing I could come up with that fit, but the placement seems awkward:
I don't own the set but found some pictures of the assembled Set 1 and Set 2

It looks to me that you can reenact the scenes of the movie with this set, therefor you have the different sections of the room, where in the movie the action takes place. You can combine the different sections to create 1 corridor by placing them as shown on page 61, the bricks of question 1 &amp; 4 can be used to connect them.

The towers are placed on the wall sections for example as: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5727533

Pages 62 and further are indeed alternative builds, I don't know if this can be done with the parts of this set, but I thibk so.