Plebescites were relatively common, which are effective referenda, giving the German public direct choice on an issue, thus being ultra democratic, with the German people being allowed to make decisions by themselves as opposed to simply having elected representatives making decisions on their behalf.
The Bill of Rights was effectively made for German workers. Trade unions were instituted to organise a minimum wage. The consideration of workers, in a previously elite class system, reflects new democratic intentions, giving everybody an equal footing. For the first time in German history everybody had freedom of religion and speech, regardless of beliefs. This is incredibly democratic as it means that all people were allowed to express themselves truthfully, no matter how extreme or unpopular their opinions were. Everyone was considered equal.
The president was politically accountable, being voted by the people every 7 years. The idea was that the president was not in office long enough to establish a dictatorship; enforcing the foundations of democracy (i.e. that a democracy is not a dictatorship.) The president appointed the chancellor according to whether or not he had the support of the Reichstag, which was in turn a representation of society. People voted the Reichstag, the majority of which had to support the Chancellor. So assuming that the people agree on who should be the chancellor, with their representatives in the Reichstag, the president appoints the chancellor based on support of the people, which is very democratic. The peoples will prevailed with regard to who the president appointed as chancellor regardless of whether or not the president himself supported him, i.e. Hindenburgs appointment of Hitler as chancellor. Thus the people indirectly chose chancellor as opposed to the president; this is democratic.
The president could dissolve the Reichstag and hold new elections if he didn’t like the policies of the chancellor, allowing the chancellor to be held politically accountable to the people. Political accountability means that people account whether the situation is good or bad, based on their personal analysis they vote. This is democratic.
Article 48 Emergency powers, existed to protect the democratic system, in the case of stale mate, or political grid lock, article 48 could be used to push through a policy, allowing the democratic process to progress. An example would be Eberts dealing with the Munich Putsch, which was successfully put down for the sake of saving the democracy.
The Chancellor and the Ministers had to have the support of the Reichstag, meaning that the majority of the elected chamber, representing the people, elected the chancellor, who appointed his ministers, which is essentially democratic albeit indirect. The Chancellor proposed laws to the Reichstag, which had to be supported by the majority of the Reichstag, who were elected by the people; thus being democratic.
However with regard to how effectively democratic the Weimar constitution was, article 48 had the potential for misuse, and it can be argued that this actually was done by president Hindenburg in the early 1930’s.
Proportional representation in practice led to very weak government, as it was so diverse; because everybody was represented, even extremists, government was weak because as so many different views were being reflected, policy making was a slow and tedious process. The longest government lasted 18 months with Chancellor worth. The whole system was extremely unstable ars it never really got its feet off the ground. Political gridlock was so common, leading to new elections, that the emphasis was put on election campaigning as opposed to policy making. The extreme parties that did get in, often were relied upon to make a majority coalition, shifting the balance of power to the small extreme parties, really undermining the whole system. The frequency of elections may well have bored voters, leading to the public either not voter apathy, with people not voting at all, or not giving sufficient thought into their choice. Extreme parties controlling power, means that the minority, is controlling the majority which is the opposite of democracy, whilst voter fatigue means that the Reichstag and thus chancellor do not actually reflect the views of the people, which is undemocratic.
The Reichstrat system allowed tiny states, to have as much representation and thus influence as bigger states, meaning that the few people in the small states between have as much influence and power between them, as all the people in the big states put together; which is entirely undemocratic.
The Bill of Rights, with minimum wages, caused disputes with employers and workers having to sit down and arbitrate wages. This actually led to unemployment as employers were forced to cut labour costs, so were employing more people. So it effectively lowers the rights of the workers, undemocratic.
So to conclude, whilst the constitution was extremely democratic in theory, the things that made it so democratic in theory like proportional representation, in practice led to plurality and diversity of governments causing an ineffective democracy for most of the length of its existence.