Power-Central Values and Engel Conditions in Prime Rings with Generalized Skew Derivations

Let R be a prime ring of characteristic different from 2 with extended centroid C, n >= 1 a fixed positive integer, F, G : R -> R two non-zero generalized skew derivations of R. (I) If (F(x)x)(n) is an element of C for all x is an element of R, then the following hold: (a) if F is an inner generalized skew derivation, then either R subset of M-2(C) or R is commutative; (b) if F is not an inner generalized skew derivation, then R is commutative. (II) If [F(x)x, G(y)y](n) = 0 for all x, y is an element of R, then R is commutative unless when char(R) = p > 0, G is an inner generalized skew derivation and R subset of M-2(C)