Solution-processable semiconductor nanocrystals (NCs) offer a versatile, highly tunable platform for low-cost, next-generation electronics. However, their integration into field-effect transistors (FETs) remains limited by the challenge of optimizing synthesis, surface chemistry, and charge transport. In this work, CuInSe₂ NCs are synthesized, and their organic, insulating ligand environment is exchanged with short inorganic ligands such as sulfides, to enable efficient interparticle coupling. The all-inorganic dispersions are spin-coated and top-contacted to fabricate fully functioning FETs. Reference samples exhibit saturation mobilities of µ_sat = 2.30 ± 0.76 × 10⁻³ cm² V⁻¹ s⁻¹ and a current modulation R_on/off = 10.4. Systematic variation of key parameters—including NC size, ligand chemistry, film thickness, and transistor geometry—provides a comprehensive understanding of the structure-property relationships, enhancing the final FET performance up to µ_sat = 12.93 ± 1.23 × 10⁻³ cm² V⁻¹ s⁻¹. This study presents a knowledge platform for advancing NC-based electronics toward practical applications.