  We study additional non-isospectral symmetries of constrained (reduced) N=2
supersymmetric KP hierarchies of integrable ``soliton''-like evolution
equations. These symmetries are shown to form an infinite-dimensional
non-Abelian superloop superalgebra. Furthermore we study the general
Darboux-Backlund (DB) transformations (including adjoint-DB and binary DB) of
N=2 super- KP hierarchies preserving (most of) the additional symmetries. Also
we derive the explicit form of the general DB (N=2 ``super- soliton''-like)
solutions in the form of generalized Wronskian-like super-determinants.
