After playing just the beginning (shortly after the father's death) my thoughts are:
sell the establishment and walk away, the mc doesn't owe anything to anyone, that girl calls him useless and if he doesn't take over she ends up in the street (she's more stupid than anything else, anyone would even try to see if he's going to keep the business), regarding revenge it's really nonexistent the mc didn't really care about his father he just has the momentary feeling of loss and worst of all they made him a loan saying he would marry the daughter when he didn't even have contact with the father xd
nothing you can't do with any save editor you can find on the interwebs.
Do you know how to add things like armor, accessories? or how to modify the level?