[en] We consider the prospects for a neutrino factory measuring mixing angles, the CP violating phase and mass-squared differences by detecting wrong-charge muons arising from the chain μ⁺ → ν_e → ν_μ → μ^- and the right-charge muons coming from the chain μ⁺ → anti ν_μ → anti ν_μ → μ^- (similar to μ^- chains), where ν_e → ν_μ and anti ν_μ → anti ν_μ are neutrino oscillation channels through a long baseline. First, we study physics with near detectors and consider the treatment of systematic errors including cross section errors, flux errors, and background uncertainties. We illustrate for which measurements near detectors are required, discuss how many are needed, and what the role of the flux monitoring is. We demonstrate that near detectors are mandatory for the leading atmospheric parameter measurements if the neutrino factory has only one baseline, whereas systematic errors partially cancel if the neutrino factory complex includes the magic baseline. Second, we perform the baseline and energy optimization of the neutrino factory including the latest simulation results from the magnetized iron neutrino detector (MIND). We also consider the impact of τ decays, generated by appearance channels ν_μ → ν_τ and ν_e → ν_τ, on the discovery reaches of the mass orderings, the leptonic CP violation, and the non-zero θ₁₃, which we find to be negligible for the considered detector. Third, we make a comparison of a high energy neutrino factory to a low energy neutrino factory and find that they are just two versions of the same experiment optimized for different regions of the parameter space. In addition, we briefly comment on whether it is useful to build the bi-magic baseline at the low energy neutrino factory. Finally, the effects of one additional massive sterile neutrino are discussed in the context of a combined short and long baseline setup. It is found that near detectors can provide the required sensitivity at the LSND-motivated Δm²₄1-range, while some sensitivity can also be obtained in the region of the atmospheric mass splitting introduced by the sterile neutrino from the long baselines.