All these and many many more questions are raised and answered here:

http://www.logicmuseum.com/wiki/Authors/Thomas_Aquinas/Summa_Theologiae

His method is quite modern: ask several sources, then give your own, all with respect. Including Jewish and Muslim thinkers. His answers do reflect his time, but they are still instructive.

Once you've checked this resource out, move on to modern authors.

You will refine your questions, which will be much more challenging, because you will still have questions, but really sharp ones.