How democratic was Imperial Germany? How much power did the Reichstag actually have? How did the Imperial German government compare to other contemporary democracies?
The Reichstag was the Parliament of the German Empire from 1871- 1918. It had less force than government, but still was very powerful. The legislature was bicameral; the two houses were the Reichstag and Bundesrat. After the Parliament of United Kingdom, the Reichstag was one of the most progressive parliaments in Europe.
Members of the Reichstag were elected by general,universal and secret ballot. All men over 25 years were allowed to vote. The Reichstag didn't have official rights to assign or disband government, and Parliament was opened once each year by the emperor. The Reichstag had rights to co-decide about the empire's budget. In order to dissolve Parliament, the decision had to be confirmed by the Bundesrat and the emperor. Then the new Parliament had to be chosen within a 60-day period, which indicates the high level of democracy in Imperial Germany.
Imperial Germany was NOT a democracy:
Only the Reichstag was elected by the people. The Bundesrat, the second chamber of the legislative, had its delegates picked by the governments of the states who nearly all reported only to the local duke or king. The Reichsregierung (administration) reported to the Emperor alone.
The election districts of Reichstag were not changed with population movement. Depopulated conservative rural districts sent one representative, and overpopulated industrial districts sent one.
The Reichstag was needed to pass laws and a budget. But the major part of the budget, defense, was passed in long multi-year stretches, reducing the times when Reichstag could demand more power.
All foreign policy, including the right to make foreign treaties and to declare war, was reserved to the Emperor.
Much power remained with the states, especially the largest, Prussia. Executive in Prussia reported to Emperor alone who was also king of Prussia. Legislature of Prussia was elected in unequal elections: voting power went with size of one's taxes.
After WW I started, much of the actual power went to the leadership of the military, especially after the appointment of General Ludendorff. The heads of the states and the civilian administrations were the losers. The Reichstag, however, kept its small rights and became the only check on the military, but a weak one. The Reichstag forced the resignation of Reichskanzler Bethman-Hollweg, but Ludendorff chose successor, Michaelis. From https://en.wikipedia.org/wiki/Erich_Ludendorff , The historian Frank Tipton argues that while not technically a dictator, Ludendorff was "unquestionably the most powerful man in Germany" in 1917–18. from Reference  = Tipton, Frank B. A History of Modern Germany University of California Press, 2003, p. 313
Others have compared Imperial Germany with Britain. But in Britain, the habits and thoughts of parliamentarism had won by 1912: the Crown and House of Lords were ornaments, not centers of power anymore. It's possible that imperial Germany would have followed the same path later, albeit it didn't in this universe.
Just to stick to the comparison of Germany and Britain: The German empire and the British empire were both constitutional monarchies, with elected parliaments, legal opposition parties, relatively free press, etc. The German emperor probably intervened more in the running of the state than the British monarch. On the other hand, Britain had much more extensive colonies than Germany with the result that a very much larger portion of the subjects of the British empire were disenfranchised than was the case wth Germany.