I think we also have to ask the question about stakeholders i.e. do you have external suppliers of data and/or do you supply data out to these stakeholders? If so, you may want to ask what format would be their preference too.
If you are starting out on the desktop, but may migrate to the web, then you may wish to invest in a Spatial RDBMS, if the project is large.
Looking at your requirements, I'd say the engineering nature of most of your requirements would point to a CAD system, which could store data on something like Oracle Spatial, which most other vendors can hoover up.
TfL have a massive Asset Management system developed with MapX on VB, and a very trick planning system for works and traffic management, all MapInfo based, but they are/were a MapInfo house.
The truth is, there are lots of COTS software that could fulfill your requirements, but all would require some customisation, in order to properly fulfill the requirements. But the important area for me is the stakeholders.