  Coulomb and nuclear dissociation of $^{17}$Ne on light and heavy targets are
studied theoretically. The dipole E1 strength function is determined in a broad
energy range including energies of astrophysical interest. Dependence of the
strength function on different parameters of the $^{17}$Ne ground state
structure and continuum dynamics is analyzed in a three-body model. The
discovered dependence plays an important role for studies of the strength
functions for the three-body E1 dissociation and radiative capture. The
constraints on the $[s^2]/[d^2]$ configuration mixing in $^{17}$Ne and on
$p$-wave interaction in the $^{15}$O+$p$ channel are imposed based on
experimental data for $^{17}$Ne Coulomb dissociation on heavy target.
