Concerning the tiller.

Make sure you can you can tuck it out of the way in heavy air when you may want to hang on to the cross bar. Also, if the tiller interferes with the sail, when sheeted hard, you can put the tiller mount on the bottom or the front of the cross bar.

For interesting ideas on tillers check the Laser Forums. Some of the ideas have problems on cats. For example, springy tillers (big round fiberglass battens, laminated wood, split wood dowels, etc) are cheap and hard to break, but they store energy and if you bend and release them, they can whack you in a tender spot. The old solid fiberglass Hobie tillers are too stiff to bend. A broken one cut to length is cheap and almost indestructible.