The latest E is not considered stable enough to use as the sole DE on Elive yet, hence the use of E16.
If you want to, you can run E24 concurrently by simply installing it: "api enlightenment" (api = alias for apt install BTW) which will pull in the needed dependencies.
The E24 installed is the latest vanilla version offered by enlightenment i.e not in anyway modded or tweaked like E16 or E17.
We do have some threads and on how to customize or troubleshoot and would advise you to look at this thread:
