((Remember that, depending on which slave devices you use, you can probably configure the SCL output as push-pull on your Cygnal device. And of course, the SDA line needs a proper pull-up resistor.))

1. No. When SMBus is enabled, both SDA and SCl are open drain with or without pull up resistors ( current generators)
2. Cygnal devices meet SMBus specification but are not only limited to.


Regards,
Cristian