AutoCAD Map 3D

[#1]

Hi! My background is in architectural drafting/CAD, and I am being nudged into GIS at my firm. I have a lot of AutoCAD experience, so going though the Map3D tutorials was not a problem...but those tutorials don't answer some BASIC questions I have. 

#1- When starting a new map from scratch, what should I set the units to? Should they stay at decimal? Engineering? Architectural? Any recommendations for changes to the Standard Settings before I start drawing?

#2- should I assign a Coordinate system immedately before drawing, or can I do it afterwards, and then "move" the geometry to the correct coordinates?

#3- When I draw, should everything be done in inches, as Civil Drafters do? Or should I be working in Feet, and real world sizes; this is what our County GIS people want when we submit drawings to them in the future. 

#4- Where can I get some georeferenced photos of my region? I understand that if a coordinate system is set and if the photos are georeferenced that they should Automatically "snap" into place for easy tracing.

#5- Is there anyone out there using Map 3D in California?

Thanks!! 

[#2]

set the coor system first along with any drawing layers you would use in each map you draw and save it as a template file so you con start a new drawing with all those items set as you like them

Units are relative to the CS you select. some are metric in meters; some are in feet indicated by the "F" in the Coord sys name  CA83-IF is cal state plane in feet . I'm not sure what part of the state that is in.

http://www.dot.ca.gov/hq/tsip/gis/datalibrary/gisdatalibrary.html   has all sorts of downloadable GIS data