Do seem edits exist for the Blackberry? Is there a way to change the splash screen to look like this:

Engadget Mobile

Currently I have the orange Cingular splash, but I like the AT&T one better. I know, it seems petty, but I had my previous phone (Moto L7) fully customized, and I'd like to know if it can be done on the Blackberry OS.

No. The BlackBerry OS is about as solid as it gets.

The only way to change the splash screen is to change the branding of the device, which cannot be done with anything available to the public.