Here is what you can do if you totally lost Citrix’s data store (the database).
From a command line on all presentation servers in the (ex) farm run : chfarm
This will run a wizard which will let you choose and configure a new DB. You will lose all your Citrix configuration. This was useful to me when I was trying to recover a small 4-5 server Citrix 4.5 farm. It was used for development purposes, so recreating the couple of published apps was not too bad.