  In the framework of minimal supersymmetry with general flavour mixing in the
squark sector we consider dominant beyond leading order (BLO) effects in the
rare processes $\bar{B}\to X_s\gamma$, $\bar{B}_s\mu^+\mu^-$ and
$\bar{B}_s-B_s$ mixing. We present analytic expressions for corrected vertices,
which are applicable in general, and provide a recipe for the inclusion of the
dominant and subdominant BLO effects in existing LO calculations. We also
derive similar expressions in the mass insertion approximation. We investigate
in more detail the focusing effect pointed out in our earlier work, which, at
large $\tan\beta$ and $\mu>0$, leads to a reduced supersymmetric contribution
to the above processes. We also find that, in some cases, flavour dependence,
that accidentally cancels at leading order, can reappear at BLO. We further
include electroweak corrections, which, while generally subdominant, in some
cases may have a substantial effect. For example, their contribution to the
charged Higgs vertex in $\bar{B}\to X_s\gamma$ can be of the order of 20% at
BLO. They can also reduce the contribution of LL insertions to
$\bar{B}_s\to\mu^+\mu^-$ and $\bar{B}_s-B_s$ mixing by up to 20%, even at the
LO. We also analyse radiative generation of CKM elements and find the
possibility that the CKM matrix elements $K_{ts}$ and $K_{cb}$ can be generated
entirely by LR insertions. This work constitutes the first complete analysis of
dominant BLO effects in the GFM scenario.
