but if you want a robot sailboat, you may want to consider a design like the planesail
it is steered from inside, with a steering wheel like a car I guess it just feathers the sail instead of reefing? this one has crossed the atlantic, so it must have seen rough weather at various points.
The good thing about this for a robot design, is that you don't directly adjust the trim of the sails (say, with a mainsheet) you instead you adjust the tailplane, which then moves the main wing(s). It uses relatively less power to adjust the tailplane (which can be balanced, for even less effort) and it can be set to keep the wing in the same orientation relative to the wind. If you had a schooner rig, you wouldn't need a rudder!
For a small scale robot sailboat, the hardest thing is making everything not break while it crosses an entire ocean (since there is no crew to fix anything) having as few moving parts is a pretty good idea.