Is it probable, given the state of the German economy, that without a war and the acquisition of territory and resources, Nazi Germany could have afforded its vast rearmament programme beyond (say) the early 1940s ?
This was the central dispute of the 'Mason vs Overy' controversy. Timothy Mason, a Marxist historian, maintained that due to the Nazi's unpopularity and economic deficiencies (some of which stemmed from rearmament) they were headed for a collapse if they hadn't embarked on a war of plunder.
While Richard Overy agreed that Germany had severe economic problems he contended that this did not push it directly into war. The war against Poland was a tactical decision by Hitler and it is unclear whether he had been directly made aware of economic issues or, if he had, whether they played much role in his decision to invade.
For a more up to date argument that Germany was pushed into war by economic necessity (at least when it attacked the USSR) see Adam Tooze's 'The Wages of Destruction'. He strips Mason's argument of its assumption that the Nazi regime was widely unpopular with the working class. Through an in depth study of the Nazi economy he argues that a war of plunder was the only way for it to face the combined alliance and resources of Russia, America and Britain.