But to answer your question, yes, you can train for MMA and not compete. Probably 85-90% of people who go into MMA never compete for a living, though some might have a fight or two, or do a few grappling or striking (boxing, Muay Thai, etc) tournaments or matches.
Of course!!! I know many people that train in mma that don't fight, typically you will spar in class, but there are many different types of martial arts, the only thing that pushes you to fighting is yourself :-) training is training. Both of my brothers, and myself have done mma, and my sister does crav... It's all a choice
About 99,9% of all MMA practitioners train and don't compete.
thats like asking if you want to own a motorcycle do you need to join a biker gang
it's called sparring
YES
I'm hearing more about the long term detrimental effects of MMA fighting. I'd like to learn it for self defense. Can you train in it without competing and still be good at it?