Creating custom ROM for Android Ice Cream Sandwich(version 4.0.3 API 15)

This project involves creating custom rom's for Android Ice Cream Sandwich (Version 4.0.3 API 15), and covers four specific requirements: 1) Remove the battery icon from the status bar display (the device is alway plugged in and doesn't not contain a battery) 2) A custom icon is to be displayed in the left of the status bar 3) The build must set the default display sleep to 5 minutes (currently it is 1 minute) 4) When the volume up/down down buttons are pressed the default stream should be the audio stream and not the ringer stream (ringer is the current default) [Note: to understand this behavior a phone will always default to the ringer stream on volume press, for a tablets {specifically Nexus-7} the volume adjust changes the audio stream]. Audio stream is the required default. The deliverables are not a complete build/rom but any .java, .mk, .h/.cpp files that are added or modified and instructions(in english) on how to roll into the work flow. Detailed/concise commenting is a plus. I want to break the project into four milestones. Each item (battery, icon, sleep, volume) as deliverable and payment when integrated into my project. (each roll in and test should be completed in 24hrs or less). Again this is not a application that merely hides the status bar or preempts the audio stream, but a change to the Android O/S itself.