Can I use ZZ (steel seal) ball bearing instead of RS (rubber seal)?
The industry term is shield versus the traditional seals. Rubber seals are usually in at least partial contact with the inner race. Bearing shields (as denoted by the ZZ suffix) do not contact either race, so contamination enters more easily than with a seal.
No bicycle manufacturers that I'm aware of spec bearing shields on any bearings. If you put a ZZ bearing in, it would quickly get contaminated, which would accelerate bearing wear.