your load questions could be easily answered with a visit from your
local building inspector or an architect.
we have our conventional washer and gas dryer on our second floor of
our 1910 constructed two story building.
when the top loader washer spins it shakes the waterbed a bit.
if the wind gusts to 50 mph, the house moves a bit.
so if either of these bother you just go to the laundromat instead.