ES, NQ, ZB. Daytrade. The 5 minute is my primary RTH timeframe. I use constant volume bar charts for the Globex session. That said, I don't take trade signals off the chart. I use order flow for that. I use the chart to keep track of intraday "areas of interest."
There is quite an extensive continuum between providing no guidance and being so highly directive that one becomes obnoxious about it. But it can't be denied that a great many new traders have no idea what they're looking at, much less what they're supposed to look for. So the "watch and learn" often winds up being a complete waste of time (they then tell others that it's a waste of time and so it goes). At least some guidance, as you point out, is necessary, and if you're with them while they're watching, no doubt they're learning quite a bit. The following addresses that but it's too much to repost, plus there's a pdf at the end of it which may be useful to some: How To Do It.
Not sure how to answer that. ES is one of the world’s most liquid markets. There are no size limitations on trading order flow. I suppose once you’re trading 250 contracts at a clip, you’ll need to be mindful of liquidity ebb and flow. But that isn’t my problem yet...
You spent how long, years?, getting to where you are in understanding. How long would it take them to actually understand it rather than simply 'parrot' what you do. Perhaps they considered trading $$$ without understanding it as unsafe. Perhaps you were clear enough that they realized that your understanding and/or what you were doing was beyond them? Seems much better than those that go 'I can do that!' and jump in betting the farm.