I will say that because the end screen code is so immediate and there's not really any room for there to be a competitive run, I'll rule that code as not legal for a speedrun. I wasn't aware of the level 2 start code, I'll have to look into that more. Though by the sound of it, it seems like something that can be allowed in a normal speedrun, at the very least in any%. It's not a major glitch and it still leaves plenty of room for a competitive run, unlike the end screen code. Thank you for bringing these to my attention. I'll update this forum on my official ruling once I get familiar with how the code works.

UPDATE

I can confirm that the level 2 start code functions equally on emulation and standard NES. In order to activate the code, players must wait on the intro scene until the text "The calm night" begins to appear next to the tree image. Then, the A button must be pressed 7 times on a controller plugged into the player 2 port. The A presses must be done before the paragraph of text is fully displayed. If done correctly, the player will start at level 2 upon beginning a new adventure. I will rule this code as legal for speedruns.