Thank you for the feedback, let me address some of the issues.
The state of the building is actually a plus for some guests, as they are looking for the "ruinous glamour" of Budapest, which is kind of disappearing. However it isn't dangerous and doesn't have hidden hazards, and as the reviews state, the apartment is fresh and clean.
In the cupboard, there are more than enough glassware for two people, including two wine glasses in the corner.
The drain in the shower has been unclogged since (too much hair).
As for the noise, only a few guests mentioned it so far and almost all of them said it didn't bother them. Yet I admit, located in the bar district it isn't the quietest area of Budapest. However from this month that will change probably, due to a local referendum for the "right to rest".
The neighbor is alright, he isn't "incredibly grumpy", just doesn't like to be woken up 3am by loud conversation at his window, when he goes to work in the morning - quite understandable. The only quiet areas is at the elevator and the corridor, the flat is the home of the guests, they are free to enjoy themselves - within reasonable limits of course.
The brown cushion and the bean bags have now been washed and refreshed, thanks for letting me know:)