'onBeforePerformAction' alternative for craft 2.4.0? Is there an alternate event for onBeforePerformAction? I want to handle an onDeleteEntry, but apparently that doesn't work on a bulk delete (deleting from the check boxes).
No, there isn't. That's why onBeforePerformAction was introduced in 2.5.

I would highly recommend that you update Craft to the latest version (2.6.2944). In addition to all of the cool features that you are missing out on, there was also a critical security update released in 2.6.2791. Without that update, you may be leaving sensitive data exposed.