I hear the Coriolis effect used as evidence of a spinning earth.
You hear correctly.
I thought the Coriolis effect was related to magnetism
Nope. That's wrong.
but a globe with a north pole at the top shouldn't change the direction of clouds and spirals in the south. It must be related to something else.
Nope. It has
two poles. A ballistic object traveling from the equator toward either pole will be deflected in the same direction the globe is rotating (east, in the case of the Earth). That's rightward if you're north of the Equator moving north and leftward if you're south of the Equator moving south. Similarly, a ballistic object moving toward the equator will be deflected opposite the direction of rotation, but still to the right in the northern hemisphere and to the left in the southern. Since the deflections have opposite "handedness", large air circulation patterns have opposite rotations in these two hemispheres.
Modern science admits that the earth is "pear shaped" or has more mass on the bottom, despite relatively little exposed land mass. Perhaps the effect is more dependent on contour of the earth such as in this model:
https://upload.wikimedia.org/wikipedia/commons/3/33/Orlando-Ferguson-flat-earth-map.jpg
The difference between the geoid (actual shape of the Earth) and the best-fit ellipsoid is a few dozen meters or less.
https://en.wikipedia.org/wiki/Geoid#/media/File:Geoid_height_red_blue_averagebw.png. This variation is primarily due to irregularities in density within the Earth. Keep in mind that the diameter of the earth is more than 12.7 million meters, so the extremes are about 1 part in about 120,000 (0.0008%).
not all toilets or tornadoes spin in that direction, the same as the flow of rivers go one way as opposed to the other, but many seem to prefer one way.
Toilets, yes. Tornados? Citation needed.
Rivers prefer to flow downhill, regardless the direction that is.
The cloud rotation I think has more to do with heat and again the contour of the land.
Large-scale air circulation patterns are always the same in each hemisphere. The Coriolis effect becomes significant at large scales (like storms the size of hurricanes), so it's harder to overcome.
I don't believe the earth could be spinning regardless if it were flat or round.
Believe what you want. It has no effect on reality. Conversely, reality
should have an effect on what you believe, but if it doesn't, that's
your problem.
the idea that it's spins faster at the poles than at the equator in a sphere is what for me proves that it is either not spinning or both flat and fixed.
Where did you get the idea that it spins faster at the poles than at the equator? That's simply wrong, so any conclusions drawn from it are meaningless.
How could someone whose body was used to going 1,000 mph since the day they were born take a trip south or north without having the change in speed wreck havoc on their insides?
You don't feel velocity, you feel acceleration. If you slow from 1000 mi/hr to zero you may not even notice, if it's gradual enough.
If less g force makes astronauts weaker, does that mean people toward the poles are stronger than those at the equator? Wouldn't the increase in force from traveling from the pole to the equator make pilots pass out?
How much is the change in net acceleration of gravity between the Equator and either pole. This has been calculated numerous times here. Unless you know, at least in general, how big the change is [Hint: it ain't much], drawing conclusions about effects it will have is only idle speculation.
I could go on, but I digress.
You haven't brought anything to the table that hasn't already been discussed.