i think it looks good so far, i agree with bergbro, better lay the bike on its side a make sure it wont be dragging on the ground in a lay down event, if made out of aluminum youd have a whole in it by the time you stop skidding, and reguardless of material it wont catch a lot if it catches an edge and gets ripped off, also you will probably need a vent of some kind for fluids to enter it properly.
also another thought you probably have under control already, if you are going to have all the fluids go to one catch can, for the coolant line you may want to have a one way valve? and/or make sure that your coolant inlet hose is at the very top and doesnt go into the container or else you will suck all the mixed fluids into radiator