Absolutely not. The idea is great, and is the undoubtedly the cheapest and easiest way to put one of these together. These are electronics we're discussing; they are dangerous in the wrong hands. If you're inexperienced with electronics or accident prone then you should not mess around with high power circuitry. Also, you'll want to pay attention to the safety features he mentions as well, the "simple circuit", as he calls it, is not the circuit he recommends implementing.

Welcome to the Farm! I am new here myself after years of lurking. The friendliest and most intelligent people have come together here making this the best forum on the internet!

Disclaimers do not make a bad design a good idea or safe. Butane cans come with a disclaimer but peeps explode every time you turn around. Your friends "extra" features do not address the real safety issues here but people do not hear what they don't want to hear and I'm not one to waste my time. Nor do I want to be "that" guy. Absolutely Not!

The circuit works....
Your plants look great and I'm jealous because I can't grow yet.... :)