I think the questions you raise, and what underlies them, are important - especially if you are a parent.
Firstly, what underlies them: why in fact should children be encouraged to be in a home workshop anyway?
One of the things that I never realised during my upbringing was the respect I had inculcated in me for those who make things with their hands.
My father, working as a research scientist and with a strong interest in radio, as a matter of course worked at home with his hands. He soldered, he drilled, he measured. He made radio things, and those things worked.
But when I was about 12 I had a whole new world opened to me. I joined a live steam model railway society, one that ran 5-inch gauge tracks in a large park. The railway used working locomotives that hauled loads of people.
These modellers were engineers of simply stupendous ability. They made patterns, had castings poured, machined those castings, used lathes and mills and hand tools. They put in lines of tiny rivets (all perfectly spaced in perfect lines), built alternators half the size of a matchbox that in turn powered real working headlights (we occasionally ran at night) and worked with danger - the boilers were legal pressure vessels.
One man in the club seemed to be able to do anything with any material - by trade he was a carpenter, by inclination a metalsmith, and by hobby an incredibly adept engineer.
I was a member of that model railway society through the most formative years of my youth, and while I never built any models, those values and mores of hard, painstaking work and the creation of things through a combination of intellect and hand power have stayed with me ever since.
And perhaps it is important that that combination of brain and hand power be stressed.
The model engineers I spent time with worked as much with their brains as with their hands, taking innovative approaches in often quite limited home workshops to turn out scintillating works of mechanical art.
And when I was about 13 and started fooling around in the shed, building speaker systems and solar heaters and putting up (what seemed to me to be) huge radio masts, it was the intellectual challenge that I most felt. Like, how could I make this broken-down cassette player (cassettes!) sound good enough for my bedroom? (The answer was a combination of chipboard salvaged from an industrial bin, a speaker pulled from an old TV I got out of a drain, and screws and glue I bought new.)
How could I make a solar water heater without having access to any copper sheet, brazing or soldering equipment? (The answer included an old 20 litre container and matte black paint...)
I think that a major reason for children to be encouraged to build things in sheds is because of the intellectual endeavour that's associated with that - and the intellectual rigour that then results from applying those skills.
Spending hours making something that doesn't work because the planning was wrong is a salutary experience - not just in making things but also in planning. Making something that then breaks is an important experience, not just in making things but also in research.
People are better for having to think about how to achieve outcomes, to achieve goals that are personally set and are dependent almost totally on their own efforts.
So I think that children making things in sheds grow up to be better thinkers - especially in planning, research, organisation and goal setting.
And they always have respect for others who do things with their hands...
Talking about hands, I think that people are also better for being creative. Deep within many of us - and probably all of you reading this - is a passionate pride in making things. To look at something and to say: I made this; that makes me feel good.
And of course to make something requires not only that intellectual effort, it requires skills with tools. I think it's good to have kids in sheds because they also learn how to use tools - and this is one area where the parent needs to work much harder.
After all, here is where safety becomes very important.
Firstly, children need to be aware of global dangers to which they are exposed simply by being in the home workshop. Welding flash, flying sparks, power tools resting apparently benignly on the floor. I think that this is simply a critical part of safety - they need to know what could bite, even if they are not directly involved.
They then need to be aware of the safety aspects of each tool that they use. It's easiest if they are introduced to this as they are being introduced to the tool. Always work chisels away from the body, not towards yourself. Look at where your fingers will go if the tool slips. The point of this small Philips head screwdriver is sharp enough to penetrate your skin.
If the dangers are covered in the same breath as 'here is how you use this tool', I think the whole spectrum of safe use is absorbed. Compare that for example with: "Now I am going to tell you about all the dangers of hand tools." How boring!
From the age of about six I chose to start my son with only hand tools. Saws, screwdrivers, spanners, a hand-powered drill, wood chisels, hammers, files. I point out to him that my worst home workshop injury occurred when I was using a hand-tool in a stupid way (it was a hacksaw), but I don't belabour the point.
I monitor him from a distance and if I see him using a hand tool dangerously, I correct him firmly, showing him why that approach is dangerous.
When he is using a hacksaw or nailing with small brads, I make him wear safety goggles - small bits of metal can so easily damage eyes.
When he is going to be spending some time in the shed, I make him wear strong boots and have full length arm and leg covering.
His first 'power' tool was a hand-cranked grinding wheel (he was the power!) and he wore safety glasses when using it.
At age eight I have just given him a mains-powered hand drill, and a 3-inch variable speed mains-powered grinder. He can use these tools only when I am in the home workshop: he knows that if he did otherwise, they would be immediately removed.
(Incidentally, his electric drill was built from half a dozen cast-offs – I always collect 1980s ‘orange’ B&D electric drills whenever I see them thrown away… and he helped build his own drill.)
He can see and understand the tool progression: he understands that a 'hierarchy of danger' exists, and that the danger level is rising, but having struggled with using the hand-cranked drill to go through steel, he also knows that power tools have huge advantages.
I'd like him to have a go with my MIG welder (it's just so easy to use) but having been warned of its global dangers (welding flash, sparks, hot metal) he sees that as too big a jump up the 'danger hierarchy' and doesn't yet want to use it.
So the safety aspects are divided into two: the home shed is a dangerous place for a child to be in, irrespective of what is actually going on; and when the child is using tools, there are further, specific dangers.
And how do you reconcile those common-sense safety approaches with the full OHS paraphernalia described in the text at the top of this screen? For me, it's a weighing up the hazard risk, and the consequences of that hazard occurring. I try to reduce that risk, and then minimise the consequences should it occur.
But after all, my son would be safest sitting on the lounge all day, playing games on his iPad....