This especially important because you can't expect the city to have to suddenly significantly enlarge the roads or improve the traffic control measures (lights, signs, etc.) overnight. If it grows up slowly, organically, then the regular rebuilding of infrastructure will naturally accommodate the building up of the area.
The massive amounts of traffic (foot\car) these things can generate, depending on the city and size of the venue. The noise from that many people on the street is not containable. The same with a new 1000 unit apartment complex going up next to you - it's going to have a massive impact on local services around you, depending on what was there already. Your idea about disallowing large changes isn't horrible.