I've been keeping up with equipment and item restock purchases despite the debt. There's not much else to spend money on, so I might as well pay the debt, though I don't dump all my money at once. I'm going to make a lot more soon enough anyway. In case you're just a bit short on cash you can always sell some of your materials. So at this point it hasn't been a nuisance at all.
It's a good thing they made the best way to make money not through generic fetch quests (although you can do those) but through the Giganto monsters which are fun to fight, and I'd do them without the money reward anyway. If Giganto monster fights were their way to stretch out the game...well let's just say they could've done much worse. I don't feel like the debt has stretched out the game much either way.
It's also a good thing they made the white color quests just generic and repeatable, and they don't appear on your job completion list anyway, so I don't feel motivated to do them if I don't want to
The important red color quests are easy.