Factory wheels = good starting point to put on a truing stand; after checking the lubrication of the bearings.
Mis-matched spoke stiffness (mixing straight and butted spokes). Not the end of the world BUT - will result in some wobble as the different stiffness spoke comes around. There will be different rim deflection. Some riders will feel it, some will not. The higher the load, the more noticeable - <200lbs no worries; >300lbs very annoying.