Some of us beginners learn from YouTUBE, but we see pros do things that are seemingly unsafe. I see it as a real issue until you develop some sense of what is prudent. This is just a few things I’ve seen that seem like big NOs for me. Am I being overly paranoid?
No, you're not. You're just being observant and questioning what you see. That's basically just smart.
1. Starting a bowl blank on a wood worm screw with lathe turning and holding the blank by hand
I rarely use a screw chuck, but this is fine in my book. Slow speed, let go when it's close, and tighten by hand. Would only do it with a (mostly) round blank - corners would be bad. Reason people do it is that it's easier to align and support the wood with 2 hands without trying to spin the wood or hand wheel.
If it makes you nervous, there's no real reason to try it.
2. Turning with fingers hanging over the tool rest. A perfect setup to crush a finger between tool rest and wood
Not with rough blanks or off-axis pieces - yikes.
I will use my fingers to support thin spindles, or the back edge of a thin bowl or platter.
3. Similarly, sanding using the tool rest to brace hand.
I will use the tool rest - moved way back - to support one wrist when sanding thin spindles where a tremor or wobble would break it. But it's unnecessary and sounds dangerous for larger stuff.
4. Taking a huge cut with a bowl gouge on an a rough bowl blank with no tailstock support with a relatively small tenon in the chuck.
I think this is totally experience-based. Large cuts in "cooperative" and wet wood, with a sharp gouge, at the correct presentation, are surprisingly smooth (and fun).
Also, it is surprising how small a tenon really needs to be if it is sized and cut correctly to fit the jaws (and in good wood).
But learning what you can get away with for both the cut and tenon does take experience.
That said, I always rough with tailstock support - but I am using an Irish/Ellsworth-ish ground gouge and the tailstock doesn't get in the way (much). With a 40/40 grind, you usually have to get the tailstock out of the way to make the cut.
5. Turning with no face shield or even safety glasses in sight.
I don't YouTube, but when demonstrating, I will use a face shield when I'm roughing things out and/or there's potential for corners of wood etc to go flying. But it really screws up the microphone and makes it hard to hear me talk. So I will often remove it when turning more predictable stuff. It's my calculated tradeoff for clarity of communication. And I try to remember to comment on my choice (but I probably do sometimes forget). The other factor for me is that the actual turning for the demo (and usually the wood blank) has been carefully chosen to make me successful in what I'm trying to communicate. So it's quite a bit different than grabbing a log out of the yard and seeing what happens. And I have no problem wearing a face shield for the whole demo if the venue/club requires or requests it.
But never without safety glasses.
I could go on and on, but are these folks just lucky or does their experience change the relative danger of this kind of stuff? and beginners trying to imitate without thinking through it.
This is a problem for beginners, as many modern beginners are relying on YouTube for their instruction. But there's nothing to go on other than their number of followers (which has nothing to do with the validity of instruction).
Is why you very often see, on this forum, recommendations to go find an AAW chapter club, and/or find a mentor, and/or take a class.
We demonstrators (and YouTubers probably) sometimes forget to think about our audience - are we demonstrating to an experienced group, or a bunch of beginners, or a mix? And we forget sometimes to comment on things that might be obvious to some - but not all - of our audience. Also, self-awareness is hard (that is, watching yourself demo and looking for bad habits that might communicate the wrong message).
So if you see something that seems questionable - do question it. A good presenter will affirm your thought or at least explain their choice for you.