Default [Q] Pasting .kl file in keyboard layout folder

Hey xda, this is my first post.

So I got an Xperia C a month ago, having wololo'd (converted) from iOS, and wow, I'm amazed from all the features that missed!

One feature that I delved into was the gamepad support. I own an XBox 360, and thought that it would be cool to try my wired controller out, especially that the C doesn't have gyroscope. I researched, found out about USB OTG, bought one, and when I got home, I tried it, only to see that the controller lights blink non-stop, as if it was searching a host. I tried a keyboard, it worked. In fact, I'm typing this post with it now. But why not the controller?

I researched and found out that it needed a keyboard layout (.kl) file to work, so I downloaded it and tried pasting it to /system/usr/keylayout but it failed. I'm knowledgeable of the rooting process to give me permission to put the file there, and I'm also informed that the Xperia C's "bootloader" cannot be unlocked because of the MediaTek chip. I also know about adb file pushing, but I'm a noob at that.

So I ask, Is there a way to root without unlocking the bootloader? If not, a way to place that one file in the system folder? I don't need a custom ROM anyway, or a root app, just that .kl file in its rightful place.