Pilot is always responsible for:
Newsky functions using real world UTC time and does not require pilots to use real time in their simulators. You can set and change in-sim time however you want.
The same rule applies to weather but be mindful to use correct QNH settings and respect wind conditions when using weather preset. With live weather Newsky always double checks your flight against actual weather in sim and real world METAR at the time.
Pilots must respect airframe limitations for takeoff and landing. List of default airframe limits in Newsky is available here. These limits however may be adjsuted by your airline, in which case please consult Fleet list of given airline.
Aircraft ZFW (zero fuel weight) will be checked during flight and compared to Newsky required ZFW generated during flight booking. Failure to meet this weight will result in passenger and cargo load recalculation accordingly revenue reduction.