I think you would make a good helper, but there are some stuff that is essential to becoming a staff member (in my opinion).
Through Meepcraft staff recruitment teamspeak is mandatory and just a great way to get out and let the community Trully know you.
Something that I love in a staff member is how they act in forums. The first dilemma is that you just need to get out there and post on some discussions and get involved. After you start participating I want to see good posts. Unbiased decisions and putting a positive end to most things gives a great impression over myself atleast.
Activity in game is a little low. And when I see you in game I don't often see you being mature in chat.
Regarding your app, it needs a bit of work.
You do not have anything voice related to allow us to know you, and you could've made up for it by making a good intro.
Use your intro to tell us about you outside of minecraft. If you deem it apropriate, tie in a story that ends leading up to your "why" section.
Why you want to be staffHere you should state qualities that you think individualize you to be a good helper and other qualities you think you have that a staff member should have. (What would make you a good staff member?) This is also the section that most people look at so try to have good sentence structure and punctuation. Some people categorize into sections such as Dedication, Activity, Friendlyness, and many other sections. Just basically make this so we know the qualities that would make you a good staff member.
Negatives/Disadvantages
This should be where you put anything you need to work on or feedback you got from a previous app/person. Anything that you worked on after getting feedback should be put here so don't be shy with putting in your weaknesses.
End your app with a conclusion going over key points that would make you a good staff member and asking for feedback, etc.