Walking on grass occasionally isn't going to damage it. What rips turf up is the twisting and scraping motions. On a penalty kick, that would be the foot you plant next to the ball. if you put a small mat down, you would eliminate most of that. The goalie is the one who will damage the turf the most. Pushing off of one foot quickly as well as diving and sliding across the grass is going to damage those areas. I'm not sure there is much you can do about that besides rotate the areas you use. If you don't play in the same spot all the time, that gives the lawn more time to recover before you damage it again.

On the contrary- many here are really interested in use of compost heap (I've used it as a very makeshift hot frame in the spring). Your setup, at least as described, may run into a couple of basic issues- first- wrapping it up like that will limit oxygen. No oxygen- no heat. If you are trying to extract heat and send it someplace, then you may try perforated pvc pipes through the bottom of the container, al the way through the compost bed, out the top to provide aeration. The bin should be raised a little to allow air in the bottom holes. Second- to get maximum heat, and to get it to last- you want a good volume of compost (at least 1 cubic meter per pile) in each pile. This is generally based on the surface area to volume ratio of the pile: a larger pile has a smaller surface area for cooling relative to the volume producing the heat. Also- heat at the center of the pile is higher because of the contribution of the heat in the bulk (more bulk- more heat delivered to the thermophiles in the middle). Larger bins, or putting them touching together will help here. Smaller bins will not only produce less peak temperature, but they will stay warm for less time as the compostables are consumed. Your reflective blanket should help this, also. The blanket should go on the inside of the bin, or at least face inwards wrapped around the bin. The outside should be painted a dark color to allow for absorbtion of stray IR from outside; we normally say that the heat is from microbes rather than the sun, but since you are literally using the pile to do work (in the physics sense), you will maximize heat production this way.

what color flowers does your varigated crinum have? I have some yellow bottle brush tree seeds.

Here's an idea. 1- go to your hardware store (home depot). Ask the guys to design you a track system to hang from the ceiling out of small metal plumbing pipes. 2- Buy canvas painters drop cloths. They measure around 12'x 10'. They are quite heavy and would hang well for the height you need. You also would not need to sew them together and would hang between the bracket supports. 3- In the drapery dept. they have grommets. Which are large circles that you fasten on the top of the panel about every 8-10" across the panels. No need to sew. 4-Hang on the rod and you are done. Hope this helps. Bonnie