[steelerborn]

Great questions.

I always like using shaft collars because they are just simple and are very reliable I have never had a problem with one, I have though with snap rings. And there is already aluminum spacers along the shafts (the blue).

The L brackets will be able to handle the transmission, but can be just bought off the shelf. And the rounds were to just minimize sharp corners but is really no big deal design wise.

The worm is a 1 in pitch diameter, and is made of steel. It has only one thread and has a pitch of 12. The worm gear is Cast Iron with 40 teeth and also has a pitch of 12. The pitch diameter is 3.33 inches.