My waterer in the coop is a flat-backed rubber bucket with nipples added to it. I'm using a round rubber dish for a lid (wedged into the top) so it can't vacuum seal. The cord goes to the lamp which is aimed at the bucket. Testing this out this winter.Not really, @rural mouse 's suggestions on cords and what to do were great. As far as waterers, I use a heated nipple waterer, got it from Premier I think. I also use a heated doggie bowl, but they evaporate quickly, so as @rural mouse ? said you might have to be filling it often if you get that.
Right, you don't need a brooder heater or a coop warmer for fully-feathered pullets or chickens, @BY Bob had that there for his young chicks when they weren't fully-feathered, and now it's handy for after-swim warmups.
I have one like he has but mine got quite hot, too hot to touch and so I didn't trust it in the close quarters of my coop. I used a heating pad they could stand and sit on instead, but only while they feathered out. I have that stand-up coop warmer now for horizontal use under the red worm bins in our very cold work room, for winter use for the worms.
But chickens do need to be out of direct drafts, yet have really well-ventilated coops. There are very good articles on ventilation design here on BYC.
I am picturing you jumping in trees.Just in case, NO chickens do not like water and while they may paddle like mad to save their lives, they can't swim and while I'm at it they can't fly either. Yes I know they can get off the ground and jump into trees. I can do that, just not as well.
The yard is small and by fencing off the pool you cut up a small yard even more. I will bounce ideas off of her but I don't usually win these things.Whether it ruins the yard depends on the style of fence, surely? Pickets, glass panels, modern style uprights, there's a lot of choice.