Welcome aboard and congratulations on your acquisition!
The issue with the LED's is an easy fix.
You just gotta turn up the volume.
I have a couple TFM-25 amps (same amp but with analog meters vs the LEDs).
The meters move very little until you get it breathing a bit harder.
I (dangerously, I know) assume the TFM-24 will act in a similar fashion to the mX.Xt series amps.
The m1.0t, m1.5t, etc all behave this way - the LEDs don't start dancing until the system is getting pretty loud.
Try turning it up (cautiously of course). Those Polks should handle all the Carver can feed it.
Just don't drive the amp into clipping!
Your Polks specs: Frequency response: 29Hz–20kHz ±3dB. Sensitivity: 90dB/W/m. Nominal impedance: 6 ohms. Amplifier requirements: 30–250W
They will handle the 225 watts the TFM will dish out.
Just be cautious and listen - if anything is unhappy it will let you know before anything bad happens.
Let us know how it turns out!