How can you add your own custom video to your iPhone/iPod on start up? I would like to be able to have an iPad2 have custom functionality. It would have a custom desktop (company logo and other icons). When the iPad2 is turned on, it would automatically start playing a pre-installed video. When the video is done play, it would go back to the custom desktop allowing the user to replay the video (via an icon) and/or click other icons to view pdf files.

I would like to be able to turn the custom functionality on and off (but this would be something only I would be able to do via a password or something similar) so that the iPad2 can be used for only this custom functionality or it can be used as a normal iPad2.

Although I know that Jail breaking is must for this but still confused that even aftaer jail breaking will it work like I want????
This should solve your video portion:

iStartupMovie is a new jailbreak tweak, which allow to play any video of your choice before the iOS home screen is displayed.This jailbreak tweak only add a “iStartupMovie Manager” to your iDevice and doesn’t effect on your other settings.

Once you have installed iStartupMovie, a new app will be appear on your Home screen. With this app, you can enable or disable the movies (MP4/M4V). Add videos of your choice to /var/mobile/Library/Startup Movies directory using either iFile (which can be obtained from Cydia).You can move as many videos into that directory as you want, in order to select which one you actually want to be played at bootup, launch the iStartupMovie Manager app and just pick your favorite video. The change should take effect immediately. There’s no apparent length limit for the boot up video but be reasonable.

You can Download iStartupMovie from Cydia’s BigBoss repository for free. You must jailbreak your iPhone before installing this tweak. You can follow our step by step Tutorial jailbreak your iPhone, iPad or iPod touch on iOS 4.3.5 using (PwnageTool), or on iOS 4.3.4 or on iOS 4.3.3

Reference:

http://techflipper.com/add-custom-startup-video-to-iphone-or-ipad-jailbreak-tweak/