Consequence of lengthening tailshaft after galvanic corrosion

[spaman]

Due to an anodic error (I can't bear to relate the long story), my tailshaft has to be replaced. One of the reasons being insufficient room to mount both rope cutter and anode on the shaft itself and relying on the anode attached to the stern tube (didn't work). Whilst most fixed blade props have an anode cap, I have a Kiwi prop which has no anode.
My questions are:

If the new shaft is made say 2"/5.5cm longer (plenty of room between prop and rudder), would the extra length beyond the cutlass bearing mean potential for vibration or possible distortion?

If the shaft is the same length, can the anodic protection be solved with a grounding bush?

[spaman]

suggested grounding bush

[senormechanico]

Not a fan of grounding brushes. (don't get me started).h
Which is more important, your shaft, prop, or catching some line?
It might be a different answer depending on where you are sailing.
Here in the PNW, it's a no brainer. Massachusetts might be different.
I added a spacer in the form of a flexible coupling.
It added about an inch to the shaft, enough for a separate zinc.
The rest of the thruhulls in the boat are bonded.