COOL triac circuit

Ok... I found this circuit that controls the phase of an ac light or dimmer using an opto-isolator.... I attached it... but I don't know if it's viewable... here's the link: https://www.electro-tech-online.com/custompdfs/2003/07/AN-3006.pdf (figure 3)

I just had a few questions I was hoping somebody could answer...

1. Does VR1 control the speed of the motor? If not, what does?

2. Ok... is there any way to send a control signal into this thing as well? What I mean is this circuit can control the speed of the motor, but can I have my microcontroller decide whether or not the motor is on or off? Does this make sense? I want to make my microcontroller decide whether the motor is on or off, and I want the VR1 to decide the speed of the motor if it's on...

any help would be greatly appreciated

FYI - generally the rpm of an AC motor is not voltage dependent though there are some exceptions - the universal motor mentioned is one of them. Just wanted to warn you in case you wanted to apply to another kind of AC motor.

thank you... I plan on using this circuit for small universal motors or light bulbs... can you offer any suggestions?