Some Scott Frederick-Weisfelt Headcanons:
He started visiting the Warehouse regularly when Irene told him that Arthur was struggling with his mental health (she conveniently left out her recent brushes with death, thinking that she was coping perfectly fine).
About 0.02 seconds after meeting Claudia he adopted her as his sister. They sing duets and rope their dad in to play piano for them.
Leena and him have been best friends for a long time. She calls him to update him on Warehouse business at least monthly.
He constantly flirts with Steve Jinks and he flirts back just to mess with Artie's head. Irene thinks it's cute.
Knew Pete's mom was a Regent before Pete did. Absolutely always teases him about it.
Corrects his dad about dates just like his mom and Myka do.
When Pete and Myka have a baby (or Pete and someone. I still want to ship Myka and H.G. Maybe there's an arrangement, who knows.) he declares himself the baby's uncle and starts teaching the child to call Artie "Zay-Zay" (his cutesy version of Zaydee). According to him, Irene gets to choose her grandma name though. Probably because she's in on it.
Will absolutely bellow-sing in the stacks just to hear his voice echo.
Calls "family meetings" just to oppress his parents. According to him they both need therapy. ("Mom, you don't get to be the strong, silent type. You are not Batman. Batman is Jewish." And "Tatti, I don't know what kind of gothic novel you think you leaped from, but you and your drama can chill.")
Makes Artie keep up to date with all of the Miles Morales comics so he can call him and discuss the latest drama. He's decided they collectively hate MCU Spiderman.
Calls Irene and Artie "Mama" and "Tatti" respectively. Or sometimes "Mrs. Frederick" in formal settings.
Wears the absolute brightest colors all the time and tries to get Irene to help him make Artie wear brighter colors. So far he has managed to get him to wear a red tie.
Will reply "Chag sameach" to Merry Christmas every time. Every time.
Used to make Artie chase him around the Warehouse as a game. Still pretty fast.
Very physically affectionate. (He gets it from his father) will touch your face, often leans on Artie because he's taller than him.
He's the one who ordered Artie's custom keyboard and monitor. Still has "dark academia" and "steampunk" tabs saved in case he needs gift ideas.
Prefers paper over digital, still often uses his smartphone. Everything has its place.
On an oral history kick, might fuck around and tour the U.S. just to hear stories.
His grandfather, Izzy, absolutely hates his piano skills but loves his vocals. He blames Arthur for not teaching him well enough. ("You're trying to do jazz piano? You can't fuck up jazz piano. You have to be good. Look, you're syncopating all wrong--")
Very good with kids, doesn't really want any of his own.