Rather than creating the shortcut by editing text preferences manually, Lloyd's FAQ recommends the keyboard shortcuts editor KeyEd Up by Jeff Almasol, mentioned previously in Modify shortcut keys in AE and Additional Scripts for After Effects CS4 (2014, at Adobe Addons).
To add a shortcut for a script in KeyEd Up, go to (category) General > Run Script and pick the number of the script you renamed as 01 [name], etc as shown by Sébastien Périer in instructions for KeyEd Up in his Top 10 list of After Effects workflow enhancing scripts.
Scripting and expressions can be intimidating, but using them isn't so much, especially with user community help. Lloyd Alvarez showed how scripts smooth workflows in his AENY presentation on AE scripting, while the Coleman and Ebberts videos on scripting talked (Flash) users through the basics. Chris & Trish Meyer's After Effects Apprentice Video Tutorial #5 provides a gentle introduction to expressions. An overview of the AE scripting scene can be found in the AEP roundup Expressions & Scripting Resources for After Effects.
Update: Lloyd added another script to his library, Add Parented Null to Selected Layers.
Earlier, Lloyd also explained How to install and run scripts:
Update 2: Lloyd has another new script, Layer Marker Rename and Number.