AMP+System tuning (for all genres)

Just installed a new system in my 2010 Toyota Camry. I'm new to car audio and would like some advice on how to tune the system (set gains, lpf, hpf, dta, etc). I'm running the following:

Head Unit - JVC KW-3935BTS

Front Speakers - JBL GTO609C Power Handling (RMS): 5W to 200W Sensitivity: (2.83V/1m) 92dB Nominal Impedance: 3 ohms

Rear Deck - JBL Stage Impedance (Ohms): 3 Sensitivity (1W at 1 meter): 89.5dB Power Handling: 5W to 80W

Subwoofer - Rockford Fosgate P2 RMS Power 400W Sealed 12 Inch Wired for a 2ohm load

AMP - Rockville DB50 85W x4 channels @ 4ohms 550W x1 A 2ohms

The JBL 6.5 components are up front, in stock locations. 6x9s are in the rear deck, and the sub is in the trunk, firing away from the driver.

The amp has gain, hpf, and x-over (full, hpf, lpf) settings for channels 1-4, and the sub channel has lpf, subsonic, gain and bass boost eq options.

My overall question:

• What should I be doing for tuning the Amp
  
• What is/are the best setting(s) for my head unit (especially setting the digital time alignment)
  

Also: when setting HPF, my amp only indicates a minimum of 15hz and maximum of 4khz. If I know my speakers minimum frequency response, (eg, 67hz) how do I set it to exactly that when there is no visual aid to tell me what I am setting to?

Thanks