As for the installation of your AV you will have to figure out the command line parameters the installer EXE has and call that from PowerShell. You can look to their documentation for information on that.
# PageFile # You'll have to use WMI for that
Get-WmiObject Win32_PageFileSetting
# Setting things with WMI will take some practice however can be easily done in PowerShell DSC
# 6 I totally disagree with # 6 and have no help to offer there plus I would never want to do that unless the machine is never going to touch a network!!!
# Install IIS
Import-Module ServerManager
Add-WindowsFeature Web-Server -IncludeAllSubFeature
# You may want to experiment with the "IncludeAllSubfeatures"
# Add to the domain I don't have an example however there are tons of examples out there but again this is easier with DSC
-VERN