I mean they are making houses as tall as low rise office buildings.Some houses even have 4 floors.
Beside the appearance I would guess on the amount of water u are trying to divertUsually square are use on commercial.
Use Aluminum gutters with the leaf guard drip edge systemYou can get them in a seamless design from a pro contractor (check Licenses )You will not have to clean themPlastic gutters ot leaf guards deteriorate (dry rot) and become brittle.
Yes.But they will have to buy it and then have it installedThe one exception to this would be the person that buys one and installs it himself.