The level choice screen cannot be bypassed. If it is confusing, it's usually because the player doesn't take the time to read the two lines of instructions on the screen.
The game will start on level one if the player does nothing and allows the screen to time out.
If the player moves the 'fire' stick to select a level, the game will start on the selected level when the timer times out.
The timer can be bypassed immediately if the player holds the left stick up and presses start.
As an owner of the game, I happen to agree with you that this combination of control inputs is more complicated than it has to be. At least it's a little awkward.
To bypass the timer, I have to hold the left stick with my right hand and press start with my left. It's not intuitive and serves no purpose. That's where players get confused. It just makes no sense. I think that it would make much more sense to eliminate the 'hold left stick' thing entirely and just allow you to press start to start. It's not like holding the left stick while pressing start provides some sort of fail safe to start a higher level where not holding the left stick defaults to level 1. If it was meant to do this, then simply timing out after selecting a higher level would default to level 1 but obviously it doesn't and that defeats the purpose of the 'hold left stick' action.
I would think that a simple ROM hack could be used to eliminate the 'hold left stick' thing. Simply changing the value of switches required to start should do it. Eliminating the text instruction would take significantly more work unless simply jumping over that text string printing code would suffice. I'd rather change the 'hold left stick up' to 'hold right stick right' and also change it so that timing out defaults to level 1.
Obviously a lot of collectors would shun such a change and want to keep it original because that's simply the way the games were BITD. Nothing wrong with that at all. It's a good rule for good reasons. Personally, for my personal collection, I'd like such a change, just like the way I like the new free play hack recently done for Space Duel that allows the attract screens to run while in free play mode. I don't mind subtle changes like that if they provide some sort of benefit and don't effect game play.
Bill B.