Family visa or work Z category which is best?

I have a Chinese spouse and hold a family Q type since more than three years back. I have the impression that after 7 years on a family Q type, one will be granted permanent resident status. Is this correct?

If this is the case, will starting working - and converting to a z type - interrupt this process and force me to start the 7 year period all over again?

Many thanks,
Jeff.