Change splash screen and lock screen under Android OS?

Question

Android

There are corporate Android tablets. You need to brand them in some way.
Is it possible to write such an Android application that changes some system functions in a "normal" way (i.e. without getting root, etc.)?
Namely:
1) replace the standard Lock Screen (unlock screen) for Android devices.
2 options are of interest:
1.1) changing the background design of Lock Screen
1.2) changing the functionality of Lock Screen, changing the method of unlocking the screen itself
2) Display a video splash screen when the device boots:
also 2 options
2.1) the screen saver is displayed right during boot, immediately after the Android splash screen , i.e. before loading the desktop
2.2) the screensaver is displayed as an application that hangs on the startup of the OS
Any advice on the implementation of these functions is very necessary.
If there are programmers who are ready to help with this, I will be glad to talk.
Thank you!

Answer 1

replace the standard Lock Screen

This program will help you: link to the android market

Answer 2

Change screensaver will only work with root