how do I create these "symbols' such that their attributes are accurate to real world and that the dimensions will perfectly match those of the architects plans? How do I answer the question when opening a .dwg regarding the X units = 1 inch?

I need to understand the procedure for creating a database of accurate elevations of devices and being able to insert them onto architects elevations rapidly and accurately.

Also, how do you draw measurement lines to show distances to and dimensions of shapes?

Thanks!

Yes, your initial assumption is correct.

You can create you own symbols any way that you want.  Once drawn (or imported, or edited) simply drag your custom symbol into the Library List under My Libraries.

Tip: you can create new folders under My Libraries by rightclicking and selecting New Folder.

To create 'measurement lines' (we call them dimensions) simply use the Dimension tool

Regarding Units in DWG: the unit of measurement in DWG files is called a 'Unit' and can be anything the author chooses, e.g. 1 inch, 1 foot, 1 mile, 6 inches, 3 feet, 10 centimetres, 12 parsecs etc. The unit's designation is not retrievable from the DWG file so this is why, when you open a DWG in Stardraw, you need to specify what a 'unit' is.  More often than not US-based DWGs are 1 Unit = 1 Inch and elsewhere 1 Unit = 1 millimeter.

You can check that you've set the correct unit designation by drawing a dimension against something whose size you know, e.g. a doorway.  If the dimension shows the doorway to be around 36" across you know you've got the unit right.  If it shows 3" you know you're out by a factor of 12 i.e. 1 Unit is not 1 inch but 1 foot.

I hope this is helpful.