To guzzijek : I suppose this practice could eventually wear out the threads of the hole and or the bolts . If it will make you feel better , install studs in place of the bolts . Use flat washers , lock washers and nuts .
To LowRyter ; To stop crossthreading , push the cover against the hole and begin turning the cover in the "off" direction . When you feel a click , stop . Now start turning the cover in the "on" direction . Practice doing this with other parts and when you feel this work you will not have any problems with crossthreading .