Faces of a CubeSat and some uses
Left/right sides – often totally covered in solar cells
Front – access port for RBF, PC link, antenna, etc.
Rear – Often with sensor, antenna, etc.+ solar cells
Top/bottom – antennas, sensors, etc. Usually the fewest solar cells here
Shock / G-loads
Not a major issue, in that CubeSats don’t seem to have much trouble surviving shake table tests and launch. Some delicate components may pose issues (e.g. solar cells). Delfi-C3
Fasteners should be staked or potted. Conformal coatings on PCBs are probably a good idea, but not required.
More and more components are RoHS/Pb-free. Aerospace technically exempt in most markets. Limited lifespan mitigates this problem somewhat.