I am still anxiously awaiting a comprehensive review of this sensor and body....
There is no "universal" anything.
In theory, this sounds like a fine camera for current Canon users (shooting non-"action"subjects) and for collectors of old and new manual focus lenses to consider. I resemble that group of users, so I am very interested, but biding my time until the reviews come out. Is the A7R shutter shock really gone? Could IBIS effectively handle 1:2 magnification with a 125mm macro lens? (dream on) Or 135mm at "portrait" distances? And then, after the reviews, does the camera/adapter/lens feel comfortable to my hands?
First, the shutter itself is said to be much better dampened so even in fully-mechanical shutter mode, there should be a big improvement.
Second, there is EFCS which the A7R does not have, which by itself removes 95% of shutter shock by removing the first curtain shutter movement before exposure begins. This also reduces shutter lag drastically (making it faster than any dSLR using its OVF).
Lastly, there is a fully-electronic mode which does not use the mechanical shutter AT ALL.
So, yes, I'd say the shutter shock is taken care of
Your other questions will depend on the user, subject, distance to subject and individual standards. You'll probably have to try it out yourself to find out those answers.