The option you're looking for is 'cheats' -> 'advance to chapter'. The biggest omission there is that the other shopkeepers stay locked.
The farm and most trainers are independent of chapter progression. The rest is mostly story quests which involve choices. How is the game supposed to make those for you? Or what 'other stuff' did you have in mind?
There are very few story events that actually block progress. The biggest obstacle to 'freeplay' is the district progression system, and eliminating that would completely gut a sizeable portion of the game's mechanics.
But 'advance to chapter 7' still covers most of it.
Frankly, my opinion is that 'unearned freeplay' makes the game considerably more boring. There is only the grind, with none of the progression, mechanics- or storywise. And I've never seen people praise such an option, only ask for it, so I have my doubts whether it would turn out to be interesting at all. YMMV.
Oh, Thanks for pointing it.
I haven`t got pass Chapter 2 on my full play, because my laptop hard reseted, and i lost all my data. (Including all the girl packs i made for myself, that i wanted to upload later); so i wanted to better see all the functions it has, in order to remade all my packs for everything the game has to offer right now. (A mistake i made with my Test Pack, which i only cover basic stuff from a fast play)
Also, as far as i know, i think there wasn`t much story after Chapter 2 (at least the guides said that), so i just said Chapter 1 because of that.
And finally, i personally don`t mind grinding-only games, tho, i still like to get most of the girls random events.
On a Side Note, i listened there was a "new version" of the pack maker coming out, so since i fixed my laptop, i was waiting weeks for that version to release, in other to make my packs "The most updated" posible.