Dixie, the risk is not so much that you might die an early death, but you have to put on your gloomy gus hat and think dark, very dark thoughts. (I'm on a sailboat board and one of the gurus says this is how he has managed to live so long sailing in the ocean--he pours a tall cold drink, sits on his porch looking at his boat, and thinks VERY DARK THOUGHTS about what can go wrong out there.)
Such as: a bus load of lawyer kids breaks down just off your property. They let the kids out to stretch. They see your nice shiny tractor just sitting there all inviting. 10 of 'em climb on it--what--the key is in it. One starts it, tosses it in gear and others flip on the PTO lever, only to gravely injure the others riding on the mower deck.
Why did they get hurt--no pto shields. Oh, but you say they were trespassing and had no right to be there.
My money says you are going to lose and lose BIG. What's worse, your insurance company might say you modified your equipment in an unsafe manner--therefore, no coverage in this instance...............................
If something bad happens, I think you want all the safety gear in place, and be able to say you were operating the equipment in a safe manner using it as designed, as prescribed in the operating manual. If you stray from this path, the lawyers will eat you up.................
Best wishes,
Ron