Controlling charge–spin conversion within a single magnetic material is important for compact spintronic devices. Using first-principles calculations, symmetry analysis, and Wannier-based linear response, we study the Edelstein and spin Hall responses of sliding-ferroelectric bilayer Fe3GaTe2. Two degenerate ground states with opposite interlayer sliding vectors and out-of-plane dipole moments are separated by a calculated switching barrier of about 16.3~meV per unit cell. Magnetization orientation determines the allowed current-induced spin components, while ferroelectric switching induces component-selective sign reversals governed by M_zT for in-plane magnetization and by M_z for out-of-plane magnetization. The Edelstein response is strongly energy dependent, with spin accumulation approaching 2 ℏ for m∥+y under a reference field of 1~V/Å. Momentum-resolved analysis links the TR-even and TR-odd Edelstein responses to Γ-centered constant-energy contours and localized interband features, respectively. Spin-conductivity contributions show the opposite momentum-space character, with broad sign-competing spin Berry curvature for TR-even and narrow Fermi-surface contours for TR-odd. The transverse spin Hall conductivity reaches ∼10³ (ℏ/e)(S/cm) and depends strongly on ferroelectric state and magnetization direction. Magnetization rotations in the xy and xz planes reveal symmetry-allowed higher angular harmonics in both spin accumulation and spin-current responses. These results establish sliding-ferroelectric bilayer Fe3GaTe2 as a tunable platform for reconfigurable spin accumulation and spin-current generation.