Hey Javier,
The admin flag is no longer need as this is the default behavior when you are authenticated with a service account. You will ignore all .read, .write, and .validate rules.
As for the debug flag, there is unfortunately no corresponding flag currently in the 3.x.x SDK, although we do plan to add it back in. We just need to figure out a new way to do it since the way we authenticate has changed and it's not a straightforward addition. That is why it wasn't in the I/O release.
Give us some time to figure it out and keep an eye out for a new release which adds this behavior back in. Sorry for the inconvenience. If you desperately need this feature, I would suggest sticking with the existing 2.x.x SDKs for the time being.
Cheers,
Jacob