You don’t need to increase your PHP memory limits unless you are getting error messages, but if you do wan to increase them mine are set to 512 under Memory Limit
When you upload the files to the FOG server from the Snapin interface, it keeps them up on the FOG server, so they don’t need to be anywhere else.
The arguments depend on the program. /i for MSIs should be fine (IIRC), but other program .exe installers might have a specific flag that they need (/silent, /s, etc)
I don’t know that you need to ever hide the arguments, but I don’t have an answer for that one.
Default has been okay for me. May need to set it higher for bigger installations like Office, but for what you’re installing I think it would be okay.
Replicate is for when you have storage node/secondary FOG servers, so if you don’t have those setup you don’t need to worry about them.
Looks good to me.
Hope that helps!