Why fly fast approaches?

EDR wrote
Prior to the flight I calculated a weight and balance and appropriate
speeds for the actual takeoff and landing weights.

This is required in large airplanes (Vref, anyone) and perfectly
reasonable in ANY airplane. All speeds change with weight. I think
what you did was fine. On the other hand, lots of people don't do it,
and simply use the full-gross speeds as published - and then maybe add
a few knots.

When we were on the ground, I asked him why he wanted the faster speeds.
His answer was that this was not a new airplane, so the book values
needed to be increased to allow for age related things that could
affect the noted V-speeds.

This is nonsense. If you have that much deformation of the wing, or
that much weight that is unaccounted for, the plane is not airworthy.

I can understand the reasoning for a student pilot

I can understand the reasoning for a student pilot too - but I don't
agree with it. Better to teach it right from the start.

I am thinking in terms of performance as would apply
to the Commercial standards. Hence, the reason for calculating the
necessary speeds prior to flight.

As I said - there's nothing wrong with your thinking.

I will add that flying at the instructor's recommended speeds leads to
float in the roundout and required more runway.

No kidding...

What is the perspective of the instructors in this group?

My perspective is that at 1200 hours, you might want to start thinking
about becoming an instructor yourself. What you experienced is,
unfortunately, more the rule than the exception, and is the kind of
nonsense that eventually prompted me to become an instructor.

Michael