That's a myth - no more dangerous than light bulbs or other electric devices. Don't pour gasoline on it or stack your newspaper collection next to it, and you'll be fine.

Cheap tube amps are a lot of fun for both music to speakers and guitar. They're also something of a lottery - a 150 dollar model can seem like a total waste and another of the same type a piece of magic. I have amps at 20 times that cost that are far less fun to use. Sometimes you pay for build quality but not much dynamism.

Go forth and experiment. Understanding marrying speakers matters more, too, but happy accidents happen. Tube amps are good for everything. I even got my cats one, apparently.