1) Thanks to the north-south alignment of the city (further aggravated by the commercial-residential area distribution along the north-south direction) there is just an extremely high population load involved in mass movement twice a day (of course, in the usual circumstances). Better infrastructure wouldn't help so much as more structural changes like redistribution of these areas or enforcing staggered working hours.
2) I feel this is more of an administrative problem - the current model of tenders does not work very well and there seems to be little or no incentive (or deterrents) for contractors to keep roads in good shape. The current road infrastructure is dismal and would require a major system overhaul to facilitate finances and will required for replacing the existing material with quiet asphalt. But yes, this probably seems more doable.
3) The municipal corp did consider having a BRTS system (a la the Bogota model) but their surveys led to the conclusion that improving the existing suburban rail system with more frequent services was more impactful. In terms of point-to-point connectivity, Mumbai certainly has very good infrastructure (especially compared to Bengaluru and Pune).
4) Don't forget about the honking! There's little or no honking in Delft.