This is something for Active Directory. Since you have a domain, all this should be configured in the Active Directory configuration.
Create the desired configurations as groups in Active Directory. Create a base configuration that will apply to each and every computer on the domain, and then create other groups to handle certain expected special cases. And then assign user accounts and computers to the groups as appropriate.
Then when they log into the domain all the necessary configurations are applied automatically.
You can even deploy software this way.
UPDATE for no AD options:
Most of these settings can also be applied via Group Policy or Registry where there is no AD domain controller.
You'll have to isolate the registry settings you wish to use, if their global settings in HKLM. But if their in HKCU (Current User), configuring one user account correctly on the machine and then copying C:\Documents and Settings\\ntuser.dat into the Default User directory of each machine (similar hardware is best for this setup, but not strictly necessary) allows the settings to be propagated for each user that logs in.
I wrote a batch script years ago that autodetected several different system aspects (back when XP first came out, we were running Win95, 98, and XP and the script could tell the difference) and then configured, based on system settings, default applications, copying our default ntuser.dat, and various other registry settings.
If I were you, I'd list each configuration you want and then find the place that setting resides on a system, then compile a registry file containing all the registry tweaks, ntuser.dat where applicable, and local group policy where that works (logon and logoff scripts, for instance, can be "installed" just by copying the script to the correct system directory). You'll end up with a collection of a few different files that you can then script together using whichever method you prefer. It's simple enough for Batch, but if you prefer VB or PS, they'd probably be more powerful.
To start you off:
Power settings are in the current user registry hive. Use powercfg.cpl to configure the desired settings and then open the registry to HKU.Default\Control Panel\PowerCfg\PowerPolicies\ and remove the numbered entries for all those setting you do not wish to be available. Do the same for each SID under HKU. Now copy ntuser.dat from the user profile you're in to the default user profile. Any user logging in subsequenly will get the power settings you've set up.