About model and data exchange with 3rd party solutions: Revit, Solibri, dRofus, Bluebeam, structural analysis solutions, and IFC, BCF and DXF/DWG-based exchange, etc.
What software do people use to collerabrate on projects? eg share files, discuss issues
We've been using a semi-proprietary system for a while at www.bimlet.com www.bluestreak.autodesk.com does similar things (it's currently a beta), eg share live feeds/streams, share & keep track of project files, have groups around projects.