4 – Can I use openQCM with a peristaltic pump ?

Yes of course you can ! openQCM is very effective in application with flowing liquids.
You can use the peristaltic liquid  pump designed by Adafruit  product id:1150. It works quite fine with openQCM. You should use an external power supply at 12VDC and connect inlet – outlet tubing for flowing the sample into the openQCM measurement chamber.