  We go on in the program of investigating the removal of divergences of a
generical quantum gauge field theory, in the context of the Batalin-Vilkovisky
formalism. We extend to open gauge-algebrae a recently formulated algorithm,
based on redefinitions $\delta\lambda$ of the parameters $\lambda$ of the
classical Lagrangian and canonical transformations, by generalizing a well-
known conjecture on the form of the divergent terms. We also show that it is
possible to reach a complete control on the effects of the subtraction
algorithm on the space ${\cal M}_{gf}$ of the gauge-fixing parameters. A
principal fiber bundle ${\cal E}\rightarrow {\cal M}_{gf}$ with a connection
$\omega_1$ is defined, such that the canonical transformations are gauge
transformations for $\omega_1$. This provides an intuitive geometrical
description of the fact the on shell physical amplitudes cannot depend on
${\cal M}_{gf}$. A geometrical description of the effect of the subtraction
algorithm on the space ${\cal M}_{ph}$ of the physical parameters $\lambda$ is
also proposed. At the end, the full subtraction algorithm can be described as a
series of diffeomorphisms on ${\cal M}_{ph}$, orthogonal to ${\cal M}_{gf}$
(under which the action transforms as a scalar), and gauge transformations on
${\cal E}$. In this geometrical context, a suitable concept of predictivity is
formulated. We give some examples of (unphysical) toy models that satisfy this
requirement, though being neither power counting renormalizable, nor finite.
