Yes, the evaporating cools down the room, though I can't say I ever noticed it. In terms of energy efficiency compared to a dryer, it's much better in summer, and not much better in winter, though you get a humidifier as a freeby.
Yes, it's a chore, a full load takes about ten minutes to hang, and it's real boring work.
The dryer wears down clothing very quickly with friction.
Cannot imagine additional longevity would be worth all the work of manually doing it.
I doubt Uniqlo clothes last five years while tumble dried. I hand dry the few t-shirts I own from them and after three years I wouldn’t wear them as anything else than bed wear.
When I used to wear business casual, I wore Next brand clothing and shirts/trousers looked the same to me even after years of drying and cleaning them. The part that starts showing wear is the fold in the collar, but that only happens a long time after I have gotten my $20 or $30 worth.
I am sure there are some visual differences between top tier clothes and what I wear, but I am okay with it as long as what I have looks clean and presentable.