Honestly, Niko can have a great maturity and attitude when he's serious, i remember you Niko has staff whiles ago, you were very mature, and i think you changed alot, in your attitude in maturity, but meh, you do what you want boy.
Just saying, as you grown up, it also means that your maturity and attitude also grown up, so if you get accepted, and work a bit more on your negative points (maturity & attitude) you'll be a great staff, and good luck for your future