Is it OK to

Take a pregnant cats temp in the last week of pregnancy to get a rough idea of when she will deliver? Or is it dangerous if you have not been trained to do it?

It's highly recommended to take their temperature, like you said it gives you an idea of when she's going into labor. If you've never done it before, and you're nervous about it, perhaps you could go to your vet and ask him/her to show you how? Otherwise just be gentle and take your time, and you'll be just fine. Here's an article for you:
http://www.petplace.com/cats/how-to-...ure/page1.aspx