I realize the former post doesn't really help you in your goal, so it's time to drop a more useful one.
First off, if your intent is to not trigger an H Scene at all, you'll want to buy a few aphrodisiacs early from the left shop and turn them into nip bandaids accessory in the right one.
This bandaid will make you immune to the estrus/lust status effect, leaving no opening for your party members to enter a scene in combat.
The first house payment is by far the roughest and can take quite a while, as you'll have to farm monkey balls in the forest and their drop rate early on is somewhat iffy. The balls are worth 2500 coins a piece. After you get Sanya money becomes less of a problem due to her having a drop rate passive and later a special that guarantees a drop.
Most monsters have a special drop if they get killed by a specific type of attack and this stays true for most if not all bosses.
I hope this is somewhat helpful and do feel free to ask if there's anything else.