Sorry - went home for the day before I saw your last response.
Here is what I did.
1 - Plot the Autocad file to PDF (I use the Bluebeam plug-in, but I'm guessing any DWG to PDF method would work)
2 - Open the PDF in Revu (I use Revu Extreme, so don't know if all these steps are available in Revu Standard)
3 - Go to Document > Security > Change Permissions
4 - Check "Enable Permissions to Limit Printing and Editing" and add a password and confirm
5 - Check "Allow Printing" (assuming you want to allow printing)
6 - Check "Allow Changes" and select "Filling in Form Fields and Adding Markups" from the popup
7 - Uncheck "Allow Copying Text or Graphics" and "Allow Extracting Content for Accessibility" (You could probably leave these checked if you want to allow it - it's Step #6 that mainly handles what you want, I think)
8 - Click "OK"
9 - Close and save the document and reopen. (It may prompt that the changes will take effect when you save. For me they didn't. I had to Save then close and open the document for the security changes to take place)
I've attached a screen shot of the settings in the security dialogue.
Also, there is a BATCH security setting so you could apply these settings to multiple files at once if you have lots to change. And in the Security dialogue you could save your custom settings to use over without having to select all the settings again.
Hope this work for you!