I think separate cloth items would be great. Always wanted that, but if so, I'd prefer each household to buy clothes for their dresser, meaning they could mix and match based from what they already got. My sims normally don't have more than 3 everyday outfits anyway. I'd much prefer mixing a limited number of clothes that would already match their style (and money). And I think each cloth would not need the everyday/party/formal branding, but leaving it to us to categorize the complete set. When it comes to hot/cold, each item could have a 1-10 value indicating how much warming it would provide. The sum of the outfit could decide whether a sim would freeze/overheat.