You dont want the fillable forms fillable at att?? not even to your own people??
If yes, why not just remove all the fillable fields and make it a regular pdf that isnt fillable..
If you want to keep the fillable but not be able to fill out, you can simply not extend the permission to reader, that would not allow the user not to fill it out in reader, however if the user has Acrobat pro they can still fill out the form.
The process of making a PDF entirely 'read only' is called 'Flattening'. I assume that you want to flatten the form after one of your coworkers has filled it in. Adobe has some very extensive server-side software that is capable of handling everything that you are asking for, but the price tag is very steep.
A free work around is to use a virtual printer to 'print' to a new file. I personally use CutePDF which is free and very easy to use. You install it as a printer on your computer, and then 'File ---> Print', select 'Cute PDF' as your printer, and then hit print. Instead of physically being printed, CutePDF will ask you to 'save as.' the new file is a pdf file that is exactly like the one you printed, but it can't be edited.
I hope this helps! If you have any other questions, just ask... I'll keep an eye on this thread.
I forgot to mention, if you have Adobe Acrobat Professional installed on your computer, there is a good chance that you already have 'Adobe PDF' listed as a printer. You can follow the above instructions, swapping out 'CutePDF' for 'Adobe PDF'. They are both virtual printers, and the both effectively flatten PDFs so that they can't be edited. I just personally prefer CutePDF.
Another neat aspect of this is that you can hide whatever you want from showing in the 'printed' version by putting the FormCalc code...:
$.relevant = "-print"
...in the initialize event of the control you want to hide. This works great for buttons. Why show your users buttons in the flattened version when they are completely non-functional? (buttons stop working after a PDF is flattened).
Just some food for thought. Let me know how it goes.