You'd still have to follow certain conditions for each party member, as (as far as I can recall), there's no way to boost their affection point outside of the side-events and some very obscure conversations - conversations with NPCs, that seemingly have no bearing on a character's opinion of Fayt, that also take place when party members haven't even been introduced, and yet these somehow ultimately tally up to Fayt's standing in their eyes - oh, and vice versa for him too. The game's flow is predisposed to Sophia - since she is the heroine as far as marketing the game is concerned, so raising another party member's standing, whilst not boosting Fayt/Sophia's affinity is pretty hard without those potions I mentioned. Like I said, it'll be interesting if anyone new here get's some of the 'harder' partner endings - especially if they did it without a guide. Particularly Maria, as much as she is a long-standing bae for me in RPGs, she can be annoying as fuck to win over. She's got a whole lot of inconsistencies to what she likes Fayt to do/be, at times she wants you to be kind to everyone, whereas she sometimes gets the most points when you are a complete arsehole.
. I gonna try to do the factory stuff. This will be my Atelier this summer