Here the incorrect statement is option C as the correct order of Lewis acidic character: $\mathrm{P}{\mathrm{F}}_5>\mathrm{S}\mathrm{i}{\mathrm{F}}_4>\mathrm{S}{\mathrm{F}}_6$ . Although, $\mathrm{S}$ has vaccant 3d-orbital but it cannot accept co-ordinate bond from Lewis base due to steric crowding factor as S-atom is already bonded to six F-atoms.
Rest other statements are correct here.