Let's see how i go. I don't have any experience with the SansAmp, but i'll say what i can.
Ok, XLR and 1/4 are the connectors on the end of cables. So you would be telling it what you're using.
Phantom, is for Phantom power. I believe some sound boards use this to send power back down the line...
I tend to just smile to myself when i see a bass that has been given the "relic" treatment. I would never pay money for one, but each to their own. A genuinely old bass, worn from years of playing, i would have more chance of paying for.
Good point. Just be aware of the "break angle" over the saddles. Pressure over the saddle decreases and you could be left with a bass that does nothing but buzz.