To answer the question re simulators, they simply are not good enough for heli ops. The graphics simply are not good enough to hover on in an effective manner (there is no 2 o'clock daisy), and the handling is just not the same as the aircraft. You can use sims (certainly our one) for IF training and for emergency training, and even for fairly effective EW training, but for low flying, winching, fast roping and USL work it just doesn't cut the mustard.
The risk to population is the main reason we don't go practicing winching from the Oxo building or lifting loads in and out of Horseguards. We can do those things to purpose-built buildings where the risks are reduced. When it comes to urban heli training the hard bits are navigation (i.e. finding the target) and the actual hover work (as your references tend to be further away). We practice the both to these purpose built places.