Yes, you should be able to accomplish all of the above using a WDC. OAuth and https are supported; in fact, we have a sample up on github of OAuth in a WDC.
Since your WDC will need to manage OAuth tokens and secrets you'll want to make sure you're hosting it securely.
Thanks for your response and the sample code. So in my case each user has it's own account and secrets so i guess we can only provide a sample WDC for them to use (as they would have to fill in their own secrets).
But i think your sample is good enough for me to review & get started.