For the lugs, 3 grunts or a good zap with an impact. For the tire pressure, depends on what tires, street, dirt ,sand and again what tires.
I run rzr2 front and back on dirt, 4psi in the rear 5psi in the front.
On sand it really depends on what tires and what your doing though. Run hauler B2B with 3psi for dunning, works good.
Size of rims plays a roll also. Just play with some diff pressures and find what works best for you.