If anyone has an idea to deal with this, please elaborate.
This is why this call only has to be made one time ; the key and secret are then securely persisted into the database and the consumer secret can be ommitted in all subsequent calls. Alternatively, we also provide an API endpoint that you can just curl to provide the consumer key/secret. Our "detailed" documentation (http://js.dotcloud.com/doc.html#c4) is more thorough on that matter.
Hope that answers your question!
Edit: sorry for the late response, happened to be out of town for the last three days. Bad timing. :(
Likewise with user accounts. If they take my keys, and somehow get someones password they'd have the same access they would otherwise have through the GUI. If I put user passwords into the code, well yeah that's totally bad on me.
I don't know. I'm not a security expert, however I've not been able to catch a problem with this. I'd love to know better.