Wheel bearing and outer seal question

I went overboard on torquing the axle wheel nut after doing a front bearing and I am wondering if I can back it out and retorque it to the right value or is it set now?
Is torquing the nut with the truck on the ground incorrect, does the wheel need to be free of weight?
Is the bearing outer seal needed ? it looks like uneffective?

Thanks so much

 

I'm not a toyota guy, and actually have unit bearings on my vehicle, but it's not uncommon when replacing spindle bearings to over torque the spindle nut, then back off, spin hub a bit, and over torque again, doing this a few times to seat the grease. Then finally torque to spec.