If you're asking if you can have a virgin run, then no, I don't believe so. No matter what, dude's going to get laid AFAIK.
I mean there was talk of adding 'evil' variations to the routes at some point, so who knows? Bloodbath run perhaps? XD
I'd suggest trying to trigger the Pete events and possibly Thea's events as quickly as possible. If my theory is correct, then you shouldn't need anything else yo clear the current main story. Heck, it may be that you don't even need Thea's story. I do know that Pete is one of the key components though.
Actually now that I think about it...
The goblin slaying quests with Eve and Sander needs to be completed, and the delivery quest (regardless of if you save Thea or not). You also probably need to do Gabe's events up to the exam, and the first training field event with Talia where she kicks your ass. I know at least the first two of those have pieces of the main plot in them, so I'd say they are essential. I'm not sure what triggers the final story event of the current story though, but Pete is definitely involved. His events are mainly; eat a fish, get his help with some paint, tell him you've hit bronze rank. Possibly some more that Im forgetting. Then the final one that ends the current main story.
I think a good indicator that you're close to that final one is Talia asking about your sword, the stating that she's going to try find time to visit him.