Gas is odorized ( mercaptans ) which can be detected at a ppb level. The great majority of people notice the smell and take some corrective action. On the otherhand ,whenever you make something fool proof , a bigger fool comes along ; so there are occasional fires caused by gas leaks. Driving a car is a higher risk that having gas in a home or apartment ...
A company called Metalcraft Engineering Company Ltd made them out of 5mm steel plate for a another company that sell nuts and bolts.
For these guys
If your objective is to use the design shown in the patent drawing or similar, you'll have to have a detent mechanism; something to restrict movement to carefully designed intervals. That's not likely to be particularly difficult to integrate into the design and you can research detents independently of this answer.
For the rotating paddle, consider that you ...
Gearboxes often use grooves in the gear and brass or bronze forks to slide the gears.
Also gears are often mounted on bushes to the shaft they run on.
Perhaps sourcing an old box or two and taking them apart to see would be useful.
This is not an exhaustive list.. but:
The air resistance and mass of the container+egg will change the impact velocity.
Deceleration distance. The container and ground will give slightly on impact. This will create a (short) distance over which the deceleration takes place. This is what crumple zones do. If you decelerate over 10mm instead of 1mm you ...
Normally all lids are provided with right-hand thread. In those cases where a layman could accidentally turn the lid on, left-hand thread is used to prevent this. An example are threaded connections for gas bottles. Probally this is agreed in the SEMI standards.
If I understand your design correctly you extend the existing play in the mechanism.
If you can’t eliminate the play then you can try to minimise it.
See the locking pliers (https://en.wikipedia.org/wiki/Locking_pliers) as an example to reduce the play. The disadvantage of this principe is the distance decrease.