I've read the fourteenth chapter now.
He lays out the need for a territorial extent proportional to a country's population -which Germany lacked- with self-sufficiency in food production and militarily defensible borders.
His ideal of a succesful foreign policy is the Ostsiedlung, as it directly added territory to the fatherland and allowed it to be settled, Germanized and ultimately become an integral German territory.
His view on overseas colonies seems to be that they're not ideal, but are still better than nothing and Germany's enemies have been strengthened by their colonial possesions.
His stance on the moral legitimacy of expansionism is that of might makes right.
He views past German borders as merely temporary results of political maneuvers, and desires to annex at least some land beyond them.
He explicitly says that a revision of borders would require war.

Most importantly, he repeatedly speaks of acquiring new territory to the East.
>Without respect for ‘tradition,’ and without any preconceived notions, the Movement must find the courage to organise our national forces, and set them
on the path which will lead them beyond the confines of the ‘living space’ which is theirs to-day, to the acquisition of new territory.
>From the past we can learn only one lesson, and this is that the aim which is to be pursued in our political conduct must be twofold, namely, (1) the acquisition of territory as the objective of our foreign policy
>It can be solved only by the acquisition of such territory for thesettlement of our people as will extend the area of the mother-country and thereby not only keep the newly-settled population in close touch with the parent-country, but will guarantee the entire territory the enjoyment of those advantages accruing from its total size

And more. This, of course, could be taken to mean "territory" as in "sphere of influence". After all, German settlers could still live in the new Ukrainian/Polish/Baltic puppet states to the East, just as the Japanese settled Manchukuo, fulfilling his vision of a "territory on which our German peasants will one day be able to rear sturdy sons".
But that's not what he seems to be implying. At no moment he speaks of puppet states, indirect control or a sphere of influence, but only the language of annexation and expansion. Furthermore, he shows himself skeptical of allying with liberation movements in other nations:
>The völkisch Movement must not play the advocate for ether nations, but be the protagonist of its own nation. Otherwise it would be superfluous and, above all, it would have no right to clamour against the past, for it would then be repeating the action of the past.