First off let me say that I am a big believer in using aluminum for just about everything, with that being said I have a couple things that I see could be problems for you:
1. With the vibration and weight of that turbo hanging it will crack that bracket.
2. Mounting to the chain case could cause the bolts to loosen and/wear against the chain case itself.
Ideally if you can make a mount that comes off the motor mounts this would be the best. Or pull a mount from somewhere on the motor. If that's not an option then mounting with a firm rubber mount will help a lot. Also if you are going to keep the mount where it is I would suggest bring a mount up from the bottom side of the turbo to help support it, this will be a big help.
Just my 2 cents
Jeff