NOTE: This question was first asked about Actions Buttons but intended the Standard editing buttons. Action Buttons are already completely configurable including dynamic visibility.
There are two sets of standard buttons.
The standard Editing buttons: Save Changes, Discard Changes, Create New, Create Copy, and Delete Entry have their visibility managed based on the table and row level security. By applying Table or Row Level security it is possible to remove each or all of the buttons.
Editing buttons can't be renamed and individual buttons can't be removed without modifying the security.
The standard Tool buttons: Mass Update, Quick Import, Quick Print, also can't be renamed but they are easily removed via the table properties.
That leaves two issue:
1) Renaming buttons: I might solve this as part of the Multilingual update
2) Hiding buttons: Database or System default on button visibility
NOTE: Please vote on this Feature Request if it interests you and provide comments as needed.