It's an invasion. Bombing was significant, yes, and I mean, Warsaw suffered. But it was mostly intact, you have to understand. Tanks and infantry are rolling in, the aftermath of invasion brings hell, but the Germans keep the systems running in Warsaw initially, because they're there to run things. The trams run, the Jews are rounded up within a year, and things are organized- they leave the water on for themselves. Later, that changes of course- people starving to death and the like says it all, then everything, everything that stands is bombed. The Soviets in the East (that is something many forget), and the Germans in the West split Poland into two, and flooded the place. What happens next is big. They create the General Government (area around Warsaw, and where they initially want to move all the Poles to) and then create the Gaus of Posen and Danzig-West Prussia, which they start moving Poles out of (Source? My mother's side of the family, down to my great-grandparents, they returned to a blitzed and ruined farm that wasn't torched by the Nazis, but by the invading Soviets, as they spoke German....it's more complicated than that). Warsaw isn't that packed before the war- afterwards, it's stuffed full of not just Jews in the Ghettos (from all over Poland) to being filled with refugees from northern Poland, and German soldiers who are basically setting up in the capital- as a extension of a German rule, and there's quite a few. In 1939, military forces, over time, reserve battalions and reserve police, mostly German, and 1944, the Germans are in full force, even the SS I believe. They had an iron grip- this is the very aftermath, barely days after the surrender of Poland, and whilst there are refugees, a lot of which ran from the Soviets who believe it or not, many were scared of (this is my father's side of the family who were unlucky enough to go to Gulags), and I do believe that even into 1944, the Germans did keep a pretty fuck off appearance to any resistance effort. This is why the Uprising is so big- because it was so large-scale an effort, it meant that the citizens of Warsaw were basically involved on a mass scale to bring about liberation for their city, hopefully to be reinforced by the impending doom that the Red Army spells on Nazi Germany.
That penultimate last bit about reinforcing of course, didn't happen in this direct order.
Also, there is one thing to note. The Soviets aren't all the good guys either. I really hate media for portraying that. Once you study Stalin, and view it in particular from Poland's point of view, the AK isn't just a liberation front. It's a terrorist organization to Stalin, and the aftermath of the Uprising is just as significant as the events before it, for the AK at least. I really hope this is something maintained- the end of this RP for many of our characters, for being merely affiliated with the AK in the aftermath (if they survive) is probably death.