i would not try the magnets as button-top simulators, especially in a multi cell light.

i would either try them as is, or solder a little blob on the top, quickly

it looks like unprotected would be ok, usually it is, for flashlights

they seem to be in parallel where you could use 1, 2, 3 or 4 cells at once.
that probably will not affect brightness, but run time would change.

wle