Exactly; the other dungeons (larger, better-paying, more fun) are only unlocked once you meet lewdness requirements AND pay the sum you owe.Thanks! So, if I evade any cutscenes, then I don't get access to other dungeons?
There's a very good chance you'll be able to pay the second sum owed even if you stay pure and only grind the first dungeon.
But the sum you owe will become larger and larger, so if you only loot the first dungeon (selling items at 50%), it'll be be more and more difficult to pay off your debts.
And even if it is possible (I haven't tried, so I don't know), you'll get bored of the first dungeon...