Yes, this will work
It can be in the rain. All the wires are on the inside.
This push buttons has holes 2 1/4" apart.
Yes, it should work. Please check if your chime requires a diode for proper operation. If it does, please install per the mfg instructions. If you do not have a diode, you may only get a single note from the chime.
No.....the voltage is very weak.