How important is the tonearm?

A great tonearm and good cartridge will outperform a good tonearm and great cartridge all day long.

I can prove that to any or all visitors.

Dealer disclaimer.

Yes, it is all important. The table, the arm, the cart, the wiring, etc. However, the OPs question was not "what is more important". He simply asked "how important is the tonearm". If they asked "How important is the table?" My answer would be the same. Very important. No component can correct the faults of another, but faults can be masked by another component.

However, the OPs question was not "what is more important". He simply asked "how important is the tonearm"

You aren't a real Audiophile. Sorry, but your logical following of "read-think-answering" is opposite to forums advices.

the basic yardstick for successful purchase is listening fatigue. In order of importance

1) turntable
2) tonearm
3) cartridge

however cartridges like speakers illicit love/hate/ho-hum responses. And unlike tonearms stylii can be destroyed in a blink of an eye. So find a cartridge manufacturer whose sound you love and settle on the model that won't cause divorce if your spouse dusts the stylus; invest any difference in your tonearm. (which may still cause divorce if your increased blissful listening hours makes your spouse feel like an "audiophile widow" :<)

You aren't a real Audiophile.

And proud of it! :-)