Three initial reactions.....
How does it react if you struck an object with the rudder?

[kvd] the clamp on the rear-end "releases" the handle, rudder goes up

It's a long reach to release it isn't it?
[kvd] rather yes, but it is only one haul, it snaps in direct

I'm assuming you still utilize shock cord for lifting up the rudder but could you add a line on the opposite path to control lifting the rudder. (I dislike the shock cord solution.)
[kvd] yes I attached the picture again, the arrow shows were the "up-line" is. It is the "greenisch/black" line with the blue tape to it

Very cool though. You're a thinker. I like your tiller arm adjuster as well.
[kvd] thanks, the bearings are from the steering rod of a GO-Kart. The "U" which holds the handlebar is the original which normally attach the tiller bar to the rudder bar

Greg