I will be doing a 20 x 20 patio with pavers, it will be 8 - 10 inches above the existing grade of the backyard, flush with the bottom of the back door threshold (basically no step down to the patio). It will have a short seat wall around the perimeter with an opening with a step to the lawn area on each side. Two planters will be incorporated into the seat wall along the back seat wall. I have never incorporated a seat wall / planter into a patio but I have done several walls and several patios. This is my thinking, give me some guidance if you can. 1) It is new construction(addition to a house) so I need to dig along the foundation to the footings and replace the backfill with what? Crushed limestone or can I use recycled process? Layered and tamped. 2) There are tree roots that I will be digging out under the proposed patio. Therefore there will be approximately 20 + inches of base under the patio (excavated roots 10"+ deep plus 10" above grade final height. I will layer and water / tamp the process in 6" increments. The base of the perimeter seat wall will be below grade as usual but I will make the base material extend out 12" beyond the edge of the finished wall. 3) We have not picked out a block for the seat wall / planters, suggestions are appreciated here. Any pictures would help also. 4) I would like to add short pillars on the two corners with lights on them and a light on each step. My thinking is to keep all the wiring outside of the wall along the base to be accessible. 5) Should I pitch the patio to the back edge with drains along the seat wall or to each side step? 5) Is it a good idea or not to install fabric under the base material? 6) Joints will be polymeric sand. Thanks in advance.