How to change TextEdit keyboard shortcuts?
Not sure how the first one should work, but I was able to assign both custom shortcuts using this:


Navigate to System Preferences->Keyboard->Keyboard Shortcuts
Click "+" button
Select TextEdit as an application
Enter "Jump to Selection" or "Select Line…" (note that there is special … symbol used, not three periods, you can just copy and paste it from here I believe) as a menu title
Press shortcut you'd like to use
Test it and enjoy!


Hope this helps.