Are new sketcher's training shoes just as dangerous as wearing high heels or platforms?

No. Running with scissors is dangerous. Running in skechers is not. High heels and platforms are only "dangerous" in pregnancy if you fall or twist your ankle. Most people are not comfortable in them later in pregnancy, but they can't cause any real harm to moms or babies. If you are comfortable in them, go ahead and wear whatever you like. Comfort and fit are the most important features.
Depending. On ones age and health status . The new sketchers can cause one to trip and fall.
They require. Some training as they have a rocker bottom. They are not dangerous otherwise. However, one should not run in them and they are not effective at "tightening posterior muscle group" if used constantly. So better to wear them a couple weeks and then stop if you want to get their toning effect.
Yes. If you are pregnant, your center of gravity changes rapidly, especially in the thrid trimester. This can make it very difficuly to maintain your balance, even in a sturdy pair of shoes. Any shoes such as heels and training shoes can add extra difficulty to maintaining your balance and put you at increased risk for falls, which can be very dangerous for the baby.