You can get 100 likes with both Bernard and Rose also with Vicoria, I think that it's also possible with Logan but I capped at 98, Hayden max is 81, Blake 54 or 56, Caleb 92, Gunnar 73 or 75, Torben 15, Scar 15, Tank 20, Barrel 35, Dulrig 52(or more but I think I capped), Ruben 11, Everett 55, Zoe 5, Booner 5, Feliar goes past 70 at moment I'm at 77 and still can get some more, Arion 98, Harold 38, Madeleine 5, Korg 80, Orgram 11, Groth 14(max but if you want 11 with the chief you can only get 13), Roghak goes past 30 I'm at 32 at the moment but I still didn't hit max, Othra 71, Rhot 70, Roushk goes past 60 haven't capped yet, Groushk goes past 30, Xeroth 62, Ste 75, Rat king 51, Scrap can go past 80 but I haven't gone there yet, Paulo 51, John 10
The people from your list that I didn't include I have the same amount of likes or maxed close to it on my old save I had 21 likes with Tao but on my recent one I have 20 since I was kinda speedrunning that part so I lost one like with him. And to get likes with Madeleine you need to kiss her in the mouth when she asks you for a kiss in exchange for teaching you how to cook and yes generally speaking having a higher amount of likes gives extra scenes with characters but I don't think there's any that's specific to having a high amount of likes since most scenes have a minimum amount to unlock and it's not really that high of a minimum