Not necessarily nasty
"any chemicals with the energy to combine violently enough to propel people to orbit will be nasty stuff."
Looked at one way, yes you have a point. But looked at another way: hydrogen and oxygen aren't dreadfully bad and are commonly used as lower stage rocket propellants (and more, in the Apollo programme at least). Kerosene (aka paraffin) is another favourite first stage fuel, although not so much these days. When I was a lad, paraffin (wax) gauze was a standard medical wound dressing which goes some way to illustrating how toxic the stuff is. Okay, okay, paraffin/kerosene comes in many different forms and all that, but I've used paraffin powered camping stoves and lamps quite a lot from childhood and the only health warning anyone gave me is "this stuff works as a laxative if you take too much of it".
The thing about stuff like hydrazine, nitric acid, and related compounds used as rocket propellants is that they're rather more easily stored than liquid hydrogen and liquid oxygen. And they can be combined in hypogolic pairs so you don't need an ignitor, thus improving reliability. So they're dead good in some ways - but if you left it up to me, they'd not be used inside our atmosphere.