Hi David,
Thanks for posting to the A360 Drive forum. Can you tell us what desktop product you are using? I know in AutoCAD these things are disabled by default and you are prompted to enable them the first time you run. You can also do a Custom Install and uncheck Autodesk 360 as an option, at least in the AutoCAD and AutoCAD Vertical based products.
You should be able to delete anything that is posted to your A360 Drive account. If you are not already using Chrome for Firefox as a browser can you try again using Chrome for Firefox. You should be able to right click on folders or files and select delete.
Hope this helps and please let us know how this goes with deleting the files.
Thanks