Setup questions Polk RTiA1 w/ Onkyo receiver

[TypicalLee]

I fished out from my basement the following items for listening to good quality music streaming (mainly Spotify premium) but also mp3s and flac files from a local UPnP server:

Polk RTiA1 speakers

• AUDIO QUALITY
  • Total Frequency Response: 50 Hz → 27,000 Hz
  • Nominal Impedance: 8 ohms
  • Sensitivity (1 watt @ 1 meter): 89 dB
  • Lower and Upper -3dB Limits: 60 Hz → 26 Hz
• CROSSOVER
  • Type: 2-way
  • Tweeter Midrange Crossover Frequency: 1900 Hz
• EXTERNAL AMPLIFIER
  • Recommended Amplifier Power Per Channel: 20 watts → 125 watts

Polk PSW 10 subwoofer

• 50-watt RMS amplifier
• Speaker-level connections
• Frequency response: 40-160 Hz (-3dB)
• Continuously variable 80-160 Hz crossover

Onkyo TX-NR717 receiver

• Stereo RMS Power (watts): 110
• THD in Stereo: 0.08 %
• Frequency Bandwidth (stereo): 20-20k Hz
• Minimum Impedance L/R: 4 ohms

I'm a noob, so I'm hoping the community can help me answer these questions:

• Although the sub has speaker connections, is it better to connect the speakers to the receiver?
• Are the speakers and receiver compatible?
• Should I bi-amp the speakers?
• What should I set for the following Speaker Configuration on the receiver:
  • Front (40Hz to 80Hz(THX) to 100Hz, 120Hz, 150Hz, 200Hz)
  • LPF of LFE: 80Hz, 90Hz, 100Hz, 120Hz, Off
• Anything else?

Thanks a ton!