They say that a sign of poor writing skills is when conflict is driven not by external forces that the characters must overcome, but by the stupid decisions made by the characters. Chapter 3 and 4 fail the test.
The first stupid decision was the MC sneaking into the room with the maid. It would have been so much smarter of him to just stay back while the maid searched for it.
The 2nd stupid decision was the MC stripping down the sleeping princess to get the key. He already knew where both the box and key were. The only sensible thing to do at that point would be to get out, tell the maid where the box and key are, and let the maid acquire them.
The conflict now is driven entirely by retard level decisions made by MC.