This is something I've pondered for over a year now, because my Kaetif creations wear clothes, and I've tried to make somewhat realistic solutions for extremely unrealistic creations. After thinking for a while, I believe, IMHO, that they are incorrect about many of their assumptions about clothes.
I think they're looking at it from a "I just put a shirt on my dog and he got pissed" standpoint. If you've been wearing clothes from a very early age, you won't care about wearing clothes. For example, collars. My dachshund /hates/ wearing a collar, but he's never had to wear one, and he's almost 14 years old. Old dog, new tricks... or clothes in this case. Our other two dogs, Midnite and Trakker, have been wearing collars all their lives, it's like second nature to them, and they like wearing it. Prolly not the best of examples, but other people constantly put clothes on their dogs, and in some cases it's recommended (like short haired dog breeds in the winter). The dogs don't care because they've been trained not to, it doesn't bother them like some people sited in their examples. Other examples would be rescue dogs who have to wear very uncomfortable and heavy vests and such. I also asked some of my "hairy" male friends, and they say clothes don't chafe or pull them much, I don't see how it would be any different for "furry" characters. In addition, their fur and skin is not as sensitive as ours, you can pull and pull and tug and hell, rip, the fur out, they don't care. This of course depends on the dog, but ours don't. Fur being pushed backwards? They wouldn't give two shits about it. I agree that the characters would be more comfortable in loose fitting clothes, but aren't most of us? I don't think wearing clothes for a human bodied animal would be any less comfortable than a human.
As for making them hot, again I don't think it would affect them any. The reason we get hot from wearing clothes is that the wind cannot evaporate the sweat on our skin properly. For dogs (again using the dog example, not the case for /all/ furry animals of course), they regulate their heat through the ears, panting, and pawpads. They don't sweat like we do, and their fur is an insulator. Infact, the worse thing you can do in the summer is to shave a dog's coat. I don't think putting on a t-shirt and pants is going to affect that much, at least no more than a human, especially since they don't regulate heat the same way we do. I mean if we wanted to get anal, there's no way a werewolf could even exist because his tongue doesn't have enough surface area to regulate the heat his body creates. So I don't really think the "heat" argument holds up very well at all.
For my kaetif, especially in Lorelei's case, they wear loose fitting garmets, like tunics and such. Their clothes are made from a lighter material because they don't need to wear clothes for the same reasons humans do. Since they are human-minded they feel the need to wear them, and also have the vanity aspect associated with it. They don't, however, like wearing footwear as much as humans because it's cumbersome, but that doesn't stop them from making their own kind of boots and such. Lorelei only wears the boots when she's plantigrade or doesn't have time to even think about taking them off.