>Scroll buttons: up/down buttons, move the list 2 positions

The first thing I would do in this situation is that I would sit down with Obi-Wan (or his hologram) and try to smooth out any problematic requirements.

"Master Kenobi, I understand that you've required a custom scrolling system, and agree that it fits very well in the unified look you're going for. However, experience tells me that this is a move we might later regret and have to backtrack on. Custom scrolling systems are currently very poorly supported by browsers, and I strongly suggest that we use native scrolling. The scrollbar can be styled, but our styling will not appear in all browsers."

And then, upon closer inspection... I realize that most of the requirements are pretty convoluted.