If you touch the cats litter box and its waste, that's the main way. Things like coming in contact, if the cat bites/ licks you, etc.
yes They can. You can check with a blacklight. It sounds crazy but ringworm glows under blacklight.
It is definitely possible. Ringworm is one of the parasites that do not discriminate against animal or person.
100%
The only way you can get it is from people who have it or people that have fungus.