I got an XYZPrinting Da vinci 1.0A at MicroCenter for a price I just could not pass up and I have around 20 hours of printing on it so far. 

1) All of my prints seam to overly smush down onto the print bed. I made a 10mm test cube and it prints almost perfectly in X and Y, but by the time it's done printing Z ends up around 9.65mm high and the bottom looks all flaired out like a trumpet... Is the bed getting to hot and the parts deforming at the base? How to fix this?  I have tried the auto calibration and also manually calibrating.  It's really messing up my prints. 

2) I'm seeing what I can only describe as snow falling on the bed during the build. Is this normal? Where is is coming from?

3) I keep getting dark burn marks in my prints and often they completely mess up the print job.

I have only been using the one cartridge of natural ABS that came with the printer.  I'm not very happy that I have to buy their cartridges, but have not got up the nerve to replace the firmware.  I don't think a cartridge reseter will work ether because my firmware is V1.0.6    

Thank You!