I would not over think the glass bed thing. I use clamps like this. http://www.thingiverse.com/thing:715545 I modeled mine myself so I can accommodate the glass thickness that I am using. I use knurled knobs on the underside to snug them down. As for glass I would go to Lowes or Home Depot and have them cut the plates to size for you if you don't want to use borasillcate.

There is a sticky in the FF sub forum dealing with dual extruder leveling. I am not sure if the Qidi is the same or not if it is it will require disassembly of the extruders to get to the screws on the back side of the heat break. from there I use a .001 feeler gauge to get them level. In that sticky there are various methods to get them back in line.

One question, Did you heat the extruder up before giving it the final tightening? If you did it cold it will be tighter than it should be when it heats up.