If you see images of your blood vessels when they shine light does that mean detached retina?

No, it is normal. Seeing blood vessels is a normal sensation during examination with an indirect ophthalmoscope. It does not mean that the retina is detached.
No. You are seeing the shadows cast by your retinal blood vessels that course on the surface of your retina. This is a normal entopic phenomena.
No. During an indirect exam of the retina (retina specialist puts on "the hat" with the light) it is common to see your own blood vessels (actually their shadows). Another common phenomenon is to shine a light along the side of your eye or simply look at a blue sky and you may see small "gnats" moving around centrally. This is called the entoptic phenomenon and actually means a healthy macula.