Hi abln, I can answer the second part of your question.Growing up, our neighbor used to run the hose in his backyard during freezing weather for us kids to skate on.Ice will not harm the lawn (which is dormant in winter)but as I remember,come spring the yard was very muddy when all the ice melted.Perhaps this problem could be addressed in planning for some kind of drainage for the rink.
there's a couple of ways to build an ice rink..ist you can just shovel out a section for the rink to be and use the snow to make banks, which will keep the water trapped so it can freeze..the other way is to use boards about 6" high..just wedge them in along the snow banks and fill with water..it will take a couple of days to get a nice thick smooth surface...a little tip to smooth out the rough ice at first...just take a snow shovel and push it around the rink scraping all the little ice bumps off...keep applying water as soon as the previous layer's are frozen...good luck..and have fun
Here is what I used to do. Put your kids on the tobogan and pull htem around to pack the snow down where you wnat the rink. Put the sprinker out and let it water the lawn. Move around to get the size rink you want. When the ice is thick enough, go out with a steel shovel and knock all the grass pionts off and get the ice relatively smooth. Start flooding with hose until you get it flat and smooth. If you use the snow for banks water it as well to make ice edges that will hold the water like a pool. Let it freeze good between flooding.