Poolmaster Across In Ground Swimming Pool Volleyball Pool Game

Can I use this on a pool smaller than 16'? I have a 12x24ft wide pool with deck around it.

can the poles on the volleyball be inserted into holes in the pool instead if using the bases

What is the diameter of the pipe posts?

If the height isn't adjustable, please explain the misleading pictures! How do I possibly play on land if the poles don't extend???