Change Permissions On A Registry Key And Other Bits From Within Program?

I am trying to write an app to automate several things that I have to do on a new computer once I have deployed an image, hoping someone could give me some pointers for them:-

1) changing computer description - wmi perhaps?

2) changing computer name - again wmi perhaps?

3) changing permissions on an existing registry key to full control

4) changing the "time to display list of operating systems" when booting from 30 secs to 3

5) turn off simple file sharing

6) and setting current user account so that password doesn't expire - at moment I do it from cmd prompt and do "wmic useraccount where "name='name'" set passwordexpires = false

7) change power plan settings so put the computer to sleep is "never" on both battery and mains