I printed ABS at .30 layer thickness , 2 layers and 3 perimeters at 30% fill with good results. Make sure the fill axis is about 45 degrees off the primary part orientation. Some parts include trimmable "beards" to prevent warping, and knobs to assist in removal from the bed.
The arm supports slide into the dovetail groove, then snap into the motor end. Fitting of many of the parts may be required, depending on your setup. Trim or sand to fit, then assemble with glue. The Avionics assembly bolts to the top with 4 of the arm bolts (the 3/4 inch or 20mm ones)
The arms should not be glued to the base plates, bolts are sufficient. Also, the avionics assembly should not be glued to the arm/base assembly.
Use 4-40 or 3mm bolts - 8 ea 50mm (2") , 4 ea 12mm (1/2"), 4 ea 20mm (3/4") to assemble the frame.
At the moment, I am using a KK controller with 2830-11 1000kv motors (cheap!) with 10x4.7 props, and a 2200MAH 3s Lipo.