[Elecraft] Elecraft K2/100 in RTTY and PSK31 Modes

[Phil, WB6TQG]

I am thinking of purchasing the Elecraft K2/100 for use in RTTY and PSK31
modes. I am a beginner in these modes. Can anyone help me with the following
questions?

1. Is the K2/100 a good transceiver for RTTY, PSK31 and other digital modes?
2. Does the KDSP2 DSP Filter help during digital operation, or does the
soundcard perform the same function? I am wondering if the soundcard makes
the KDSP2 redundant.
3. Do you recommend the KNB2 Noise Filter for digital modes?
4. Any other comments are welcome.

Thank you very much for your help!

73, Phil, WB6TQG