Would anyone with an understanding be kind enough to summarize how to move an app with all its files and preferences to

[Monster]

you used to be able to do it like this, maybe you still can

Steps to migrate a keychain

Go to ~/Library/Keychains/ and make a copy of your primary keychain (by default it is called login.keychain).
Rename the copied keychain (e.g. username.keychain)
Move it to the same location (~/Library/Keychains/ ) on new computer
Launch Keychain Access (/Applications/Utilities/Keychain Access)
From the top menu, choose Edit > Keychain List
On the available keychains list click the "+" to add a new keychain and locate your username.keychain which should be located in your new ~/Library/Keychains/
Click OK
To the left you will see a list of keychains called "Keychains," select you new username.keychain and unlock it (click the padlock icon in the top left corner of the window).
With the username.keychain still selected, from the top menu, pull down and select "Make Keychain "username" Default
Choose Keychain Access > Keychain First Aid and run it.