While that is a good point that we must "kill our babies" sometimes, if there's anything I've learnt from this production is that the snake worked. 90% of my positive feedback has been about the snake and it has made me glad I took the extra effort to get ahold of the man who owned it.
Yes, 90% of the positive feedback you've received has been about the snake scene but to develop your skills, you have to ask yourself why. Is it because the feedback is from filmmakers who appreciate how difficult that scene was to film or is it purely because you maximised the dramatic potential of the scene? To an audience of the general public, only the latter is of any real importance.
Look at your short again but this time as a member of the audience rather than as a filmmaker. Feel the energy and pace from the boy falling in the creek and the girl running for help through the grass, now feel the fear and dramatic impact of suddenly finding yourself face to face with a snake. You can't, it's not there! The energy, pace and dramatic impact has virtually disappeared! Your film still probably works better with the scene than without it but works fractionally as well as it should have. I'm not suggesting you learn how to compose music (or sound) yourself or even that you should find significant budgets to hire music and sound professionals. I'm saying that as the Director, it's up to you to direct whatever composer/sound people you do have! In this case, that would have meant making it clear to the music/sound person/s that the snake scene should present more drama and fear than the running through the grass scene. As with the opening scene, you have directed what the audience sees well ... but it's hard to imagine how your directing of the sound/music could have been worse because instead of enhancing the storytelling you were trying to achieve with your visuals, the music/sound does the exact opposite and fights against it! The audience ends up getting half the emotional impact, excitement and entertainment value for which you as the director are responsible.
Just to be absolutely clear, I'm NOT talking about the sound equipment you have or your budget for sound/music but I am questioning your professed "respect" for these aspects of filmmaking. I'm questioning the level of your directorial skills of the visuals, compared with your directorial skills for the audio side of filmmaking. You need to be good at both to be a good director! Your composer was obviously not a top professional but was perfectly capable of creating different energy levels and emotional "feels". So in this film, the fact that he/she often created an inappropriate pace and/or feel is more of a directorial issue than a budgetary or compositional issue.
Creating something which "works" is a great achievement and I applaud your efforts but now you need to start thinking beyond this first step. If your filmmaking idol is for example Spielberg, then you need to start thinking like Spielberg, you can't just limit your thinking to that of whoever Spielberg's DOP is or even to that of Michael Kahn!
Again, I'm not saying this to try to insult or discourage you, the opposite, I'm suggesting how you can most obviously improve you directing skills at no cost beyond adjusting your thought processes and spending some time studying how sound/music is employed by the great directors/filmmakers.
G