Caroline: Lydia EW! They do not get on. Knightley is very handsome and definitely eligible (how big is his estate again?) She would not mind getting to know him more. Henry will definitely be fun for flirting, and he might even get her to loosen up. Anton, she is intimidating ;)!
Cathy: Lydia would be like her friend she has with Isabella, so definitely some bad influence there xD but mostly they are silly. Mr. Knightley is so very nice, and Cathy finds him very gallant (but he is old...). Henry makes Cathy BLUSH! And it would be nice to find someone to talk to about novels, with Anton!
Wentworth: Lydia is a charming girl, but he wonders just how sensible she is. Knightley and him should be friends! Henry, he's not quite sure what to make of him, or if he's trustworthy. With Anton being friend, Wentworth will try not to hold that against him haha. But yes help with his memoirs would be great!
Tom: He's the untested one so far. He wouldn't really pay attention to Lydia, unless she was interested in one of his plays. Knightley he'd find attractive but if he is so gallant, he might not risk exposure there unless Knightley showed interest. Henry IS someone he can be friends with because they were :D! And Tom might be more than willing to show interest that way as well. Tom is friendly, and will talk to Anton, and he'd be interested in his writing.