Luckily with a little PowerShell you can easily spit out all of web application properties.
Get-SPWebApplication http://sp2010 | Select *
Here is the output:
Pretty cool, all our properties are right here, no need to go into Central Administration and poke around, sweet! We can take this a little further and output the properties to a text file.
Get-SPWebApplication http://sp2010 | Select * | Out-File c:\web-app-settings.txt
Here is the ouput:
Now that we are sending the output to a text file, nothing is shown in the window. However, looking at the C: we now have a new text file:
Opening that file, we can see all of our web application settings have been saved off for us:
And that's it! You now have a text file with all your web application settings for review or for future scripts.