Q1. Two dynamic columns on one page.
Current tweak does not support this. You have to know in advance which column will always be longer and place it in the dynamic placeholder. If this is impossible at all and any appropriate redesign of the page is not an option, then let me know and I may provide improved script with multi-column support.
Please add this, especially useful for long category menues and actual page content that are both dynamic. Page content would usually be longer than menues but not always.

Also how do I add this dynamic page to a website? Double clicking it opens a new site I think, do I copy the page into other site some how?