1. If cabinet work, why 2.5/3D?
2. Machine is fine, what you see is remnant of circle being freed from host material without circle being held down adequately (learning tricks with vacuum will cure that, no problem).
3. Tough call, used car/new car.
Machine looks in good shape, seen a couple of Gerbers that looked worse than that, and they performed. Looks like a decent spindle. Not familiar with E-Z routers, if they are Chinese made, it would be an easy decision for me. In this economy thinking you might pick up the Gerber cheaper than you think.