I would suggest that you read Connelly and Brendan Simms to start with.
Westphalia was created from Hesse-Cassel, Brunswick, and parts of Hanover. The new kingdom was given a constitution, which was a reform in itself, as well as legislative power over taxation and the Civil Code applied. Feudalism was ended and equality before the law was now an established principle. There was both civil and religious liberty and the Jews were granted full citizenship. Guilds were suppressed and even peasants sat in the Standeversammlung. And the power of the Church was greatly reduced.
Jerome's ministers were mostly Germans, not Frenchmen and bureaucrats, judges, and magistrates were trained and employed.
Problem solving by legislation was introduced and most, if not all, of these needed reforms were new to the disparate territories that made up Westphalia.
The debt was not good for Westphalia, and was a huge burden on the kingdom, which is why peace was needed to consolidate the new kingdom.
But the idea that you keep repeating that Napoleon drained the Confederation states of funding, or robbed, is just not accurate. As Owen Connelly notes, 'The idea persists that the satellite kingdoms were 'robbed' for the benefit of France. One envisions wagons rolling toward Paris with coin for the imperial treasury...As to treasure wagons, few indeed came from the kingdoms to France. The states contributed largely by supporting French troops within their borders; much of the money they supplied was spent locally, either by army buyers or the troops themselves, to the benefit of native merchants and producers...the tax rate in France was always higher than in the kingdoms.'-Owen Connelly, Napoleon's Satellite Kingdoms, 341-342.
The bottom line is that the Confederation states were much better off being allied to France than being under the thumb and the threat of absorption by either Prussia or Austria. Austria had invaded Bavaria twice as an aggressor in 1805 and 1809, and, especially in 1809, the general response from the Confederation was outstanding and contributed greatly to Austria's defeat.