I am watchin' this forum many years ago but never actually posted anything...
So about semi automatic gearbox.
Several years ago some posted about that,
@reca made detail post about that
whole disscusion you can read it hereAn abstract, I hope it answers, at least partially, your questions.
In 1978 Mauro Forghieri designed a system that was mounted on an old Ferrari 312 F1. It was composed by hydraulic actuators (taken from a machine tool) moving the selecting forks in the gearbox. The shift was actuated by two buttons on the steering wheel, one for the upshift, the other one for the downshift. Gilles Villeneuve tested it on the Fiorano track making about 100 laps successfully. But at the end of the test he said that he wasn’t confident without a mechanical link, Enzo Ferrari accepted the judgement of the driver and the system wasn’t further developed.
About 10 years later John Barnard introduced on the Ferrari F1/89 (640) the semi-auto gearbox with paddle shifter behind the wheel
http://www.f1technical.net/forum/viewtopic.php?t=884