"Leuf" wrote in message
...
So here are my questions,

With the proper joinery should a frame survive a fall like this or
should it be expected to fail?

Should I be making the spline deeper or adding a key for additional
strength?

The frame was made to hold something, not to protect it from a fall.
Especially when what's in it is very heavy. If you want protection in a
fall, you'll want something besides miters, keyed, splined or otherwise. A
sharp blow is going to break small glue surfaces apart.