Let's play the "Have you ever..." game!

There is an option "ask to see outfit" in friendly social, the targeted sims will change into the category you want to see. They'll keep the selected outfit until the situation needs them to change to required ones like swimming, sleeping.

As for why your Malcolm Landgraab dressed in underwear for no reason, I soft of encountered a similar, but worse experience! The pre-made celebrity Kayla Flemming invited my sims to a charity event. When my sims arrived, she stood there without any cloth! I asked her to dress in formal, she did the change outfit action but still in nude. She ruined it all! (Imagine how much money she could raise by doing so! LOL! We don't have to go in this extreme way. right? Even if it's for good!) Then I went to CAS, finding out her formal outfit was nude! I decided to check all the NPC, it turned out there were half-naked ones in my game. And they all had something to do with my CC. Once disabling the random CC for NPC, I've never seen any naked sims anymore. Remember if you remove or disable a CC, those NPC who had dressed that will lose that part of clothes. You have to dress them "yourself"! Otherwise, the missing part will become nude.

I should remind players that once a sim age up, he/she outfit will change into another different "age" category, which means it's a big change. Malcolm Landgraab is a teen in the beginning, once he ages up to YA, his outfit might glitch, resulting in some weird outfit if the game doesn't do it right. Anyway, just use CAS to change NPCs' outfits, they don't know how to dress unless you do it for them.