The manufacturer does not provide this information. You will need to reach out to them directly to verify where the Diamondback Tactical is assembled/manufactured. Here is Vortex's contact information:
https://vortexoptics.com/contactus/
Medium, with a 44mm objective medium should be just fine.
No, not illuminated.
It comes with a sunshade.
Vortex lists the following caps for the eyepiece and objective:
https://www.opticsplanet.com/vortex-defender-objective-flip-caps.html?_iv_outer-diameter-699615208=range-41-dot-5-46-mm
https://www.opticsplanet.com/vortex-defender-objective-flip-caps.html?_iv_outer-diameter-699615208=range-48-53-mm
This scope does not include rings.
In this case, the only difference is color and price!
This optic does not have locking turrets. That feature can be found on the Strike Eagle 3-18x44, SKU SE-31801/31802
This is an adjustable parallax model, in fact!
The Vortex Diamondback Tactical FFP 4-16x44mm 30mm Tube First Focal Plane Rifle Scope features the Vortex Unlimited Lifetime Warranty at no additional cost. Vortex will repair or replace your Vortex product in the event it becomes damaged or defective—at no charge to you.