I finally managed to get around to editing my own animations, and I'm damn happy about it.

However, I still have a few questions:
Is there no way for me to change the length of an animation I want to create?
(if say I want to make my own jump animation or something, and I want to make it longer - or shorter - can I achieve that? For now, I only managed to create 1 second animations)

you can edit the animation by doucle clicking on his name in the directory, and you will be able to change his speed, loop, and other params depending on what you want.

I know that. But none of those options allow me to control the duration of the animation. When creating a new animation, it lasts the default 1 second.
How could I increase that?