The most recent statistics show that around 6% of truck drivers are women, despite making up 47% of the total workforce.
It's no more dangerous than it is for men, or for any other occupation. As always, be aware of your surroundings and stay alert. If you can handle yourself as a civilian, then you can handle yourself as a truck driver.
Not really. Trucking is one industry in which the playing field is leveled, so that if you prove you can do the job, it doesn't matter whether you are a man or a woman.
Most can, barring any specific medical conditions. Most driving jobs will be mainly "hands-off", unless you get into flatbedding, etc. Again, there is nothing about the job that prohibits a female being able to handle it any differently than a man.
Usually, yes, depending on your preference. You may have a longer wait for a female trainer, however.