This answer is: wherever the fireplace is, if it's already built into the house. If you're installing one of those new fireplaces that don't require a chimney, then you put it wherever it will work the best with how you live in the house. It's not a matter of whether it's front or back, but what works with the flow of living.

You should put it where you will get the most use out of it. If you have any area of the house that has a better view than another, take that in to consideration.

well, certainly the view should be taken into consideration, but also the prevailing windflow. In very cold climates, a somewhat protected area will lead to more enjoyment of your outdoor fireplace. although not in a screened porch, here is a photo of my outdoor fireplace...

I agree with all of the above.

What type of stone is used for the steps & walk way? And is the stone used as edging around the patio the a different type then that of the walkway stone?