Is there a cap to the skill levels? Currently mine are all 100+ each
99 for conversations, 999 for base stats. It's gonna take a while, too - because stats are only given out at job end, not per additional tacked on hour - so for example speed raising stamina is a bunch of individual food delivery jobs.
It's best to just grind out a high stat level during episode 1/2 before you get busy.
Conversation and taste raise your stats with haruka / let you skip conversation topic grinding at a certain point when you get the "improvise" ability.
Raising knowledge past about 300 lets you get 15-20 knowledge stat gain for every hit on "philosophy" so you can get that high as well, which means you can easily get excellent reports, which add bonus score to your part time job money.
It's a fuckin grind though, but there is so much content that you can fairly easily raise the stats to max during the rest of the gameplay after grinding up stamina super high early on. Game makes you work for it, though. Content wise it's far better than the first game, and there are little secret perks to string you along before you finally get it.