Have given my thoughts & impressions, and some additional ideas/alternatives
Abbott - like in theory but the sound is a bit harsh and quick sounding (rabbit like) to me. It does give some cool nn’s though (Otto, Bob, Abby, Abe). There are other southern style gent names I prefer though (Ford, Jennings, Fletcher, Brooks, Callahan, Beckett, Bennett).
Anders - I like this name! It’s cute-guy Scandi and immediately likeable.
Clark - a bit intense and earnest for me but it is distinctive and noticeable.
Elliott - this also has a nerdy cute vibe, it’s a little less mature sounding as your other names but very lovable. Everett has a bit more heft to it, and you might also like Julian or Oliver.
Francis - grew up with a guy I knew called Francis and he struggled with thinking his name was a girls’ (Frances). I love Francis but would use only as a middle, including so it’s not shortened to the honky sounding Frank.
Hirsch - middle only for me. Giving his & Hirsch. What about Hayden, Hayes, Harrison, Hugh or Hugo?
Ives (middle name only, legacy) - love it, but get why middle only. French pronunciation is so handsome!
Madoc - not quite hitting mark for me, almost hear manic when I say it. How about Cormac, Malachi, Marcus, Max, Tiernan, Emrys, Lachlan, Jacob, Ronan, or Tobias.
Reid - I like this name - it’s smart and authoritative - but it reads (lol) super American. That isn’t a negative - you are American - but just if you’re going for a more Brit/international feel this might not be the name. How about Rhys, Rafferty (nn Raffy, Raffa, Rafe), Rory, Gabe? (But I do think Reid should syst in the list, it’s a good name.)
Stellan - very handsome! Just need a good nn. Also like Sterling, Silas, Cyrus, and my fave boys’ name, Sebastian.
Warren - this is a really rough, dated (1980s) name where I am (Australia) and has no good nicknames (would get Woz or Wazza). How about Wesley, Wyatt, Marshall, Xander, Arthur, Evren or Dylan? I also like Weston, Murphy & Walter.
Willem - this used to be a fave of mine! Still really like especially if you have any Dutch heritage.
Hope that helps! If you have time, let us know if any appeal.