I changed the default Minecraft directory by adding a key and a string to the info.plist file of Minecraft.app.

Works fine, no new issues have occurred ever since, except this one:

It constantly check for BOTH directories, instead of the one I set as default. I know this, because every other time I launch the app, it takes slightly longer to open than usual, and my saved Username and Password do not get inserted. When I look back to the old directory, which is the /Users/*/Library/Application Support folder, there is a blank minecraft folder. If I delete it and launch the app again, it goes for the directory I set. When I quit playing and start the launcher again, it does the same thing: create a black directory in the default location.

I will provide the strings I added to Minecraft.app below:
(The first 2 lines should be disregarded, they are just for reference as to where the new strings are in the document. I will denote the new lines with a # symbol.)
<key>sun.java2d.pmoffscreen</key>
<string>false</string>
#<key>user.home</key>
#<string>/Users/Redacted/Desktop/Redacted's Stuff/Applications/Minecraft/Saves-Current</string>