Not using the car for two weeks
No it will be fine unless you have something drawing from the battery
Absolutely not, in fact I would get a float charger and install it and then plug it in before you leave. Disconnecting the battery can cause a loss of factory presets in the computer systems and then you woolly windup at the dealership getting it reflashed.
Well I'm late to the "no" party, but still want to chime in - pick yourself up a float charger and leave it plugged in, no need to disconnect battery. In fact disconnecting a battery can cause a lot of issues on car these days.
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