Lets be clear on nomencalure: You don't want to delete the account. You want to delete the account's homefolder on the server. Correct?
I don't believe there is anything in OS X Server that manages account folder deletion (there are login controls, but the data would still be there). You could easily write a script however to delete the home folders. What is your experience in shell or Applescript?
You don't need to restart the server to run a script, delete folders or even manage accounts. If you want to write a script that launches at regular intervals, you can do so using launchd.
Does that help?
OK, well, scripting it is. What you'll want to do is iterate through the accounts with dscl, checking mobile status, and remove the entry and the appropriate home folder. Let me know if you need some help with that.