Hello!! For Florian and Elisabeth I have Venusia Crickerly and Lester Hatchitt - Elisabeth would remind Venusia quite a bit of herself, so she'd be moderately more friendly than one might expect. Florian wouldn't be likely to get a ton of empathy from her, but Lester is a deeply nervous person who would probably try to give Florian some good-natured advice. or if you want a "have you considered getting a grip," interaction there, Venusia could deliver!

For Thomas, I have Cash Lestrange - an 1884 graduate and former professional Quidditch player. Cash is generally rather distant with people and his family is far more conservative than Thomas is, but I can definitely see them being casually friends because Quidditch was Cash's whole life, too.