Can I model objects using real world measurements in 3D Modeler?

Hello - I am considering 3D Modeler for some simple projects but can't currently use the free trial because my graphics card does not meet the specifications. If Modeler can do what I want I will upgrade my graphics card, but thought I would get input here first.

I use the full Adobe CC apps daily for for graphic design, image processing, and 2D technical drawings for brochures, instruction manuals, etc. Occasionally I could use some basic 3D models and I would be very intersted to know if 3D modeler can do this. 

Is it possible to use real world measurements to model objects? All of the demo videos i see are for fantasy objects / toys with people just creating freehand with no actual accuracy in placement and spacing. I'd need objects to be exactly X by Y by Z dimensions with specific thickness and have holes drilled at specific locations and trim at specific widths, etc. Is this possible to feed in actual measurements? I don't need internal details or mechanics but basically a cube form with some extra bits. 

The next step of this process is to be able to composite this object into a photograph of real objects. I see that Photoshop is depreciating it's 3D features (which didn't match perspective of the photo anyway). Is this a feature available in the 3D Stager application? Can I build an object in 3D modeler, add color in Substance Painter and then stick that into a photo in Stager? 

I have tried in Blender but it is cumbersome and much more indepth than I need and not really geared for this type of application. 

Anyway, thought or ideas on how I can achieve a "seemingly simple" task are appreciated.