I think you should be able to apply for staff below the age of 15. For example, I am not the age that I am supposed to be to apply for staff on Cubedcraft.
Other people do want to become staff, but they would get a lower rank. Like, Trial-Mod. That would be an option for the applications that are under the age under the original forums page for applying. Although, you do need to be at a higher level of maturity to get the job of staff. I think that 11-12 year old people, should be able to apply. But they would need take a maturity test to see if they are fit for the job. I was thinking like a list of things you would need to choose. Then, write down your opinion, and why you would like to be staff. Maybe more questions.
I think people under the age of 11-12 should be able to apply for staff.