Sorry, I inserted my responses into your quote...does that not come through to you? Just a minute, then...
1. The horizon always appears perfectly flat – except in NASA and other government pictures, which are obviously faked (as part of the global conspiracy)
but the degree of "curveyness" is smaller than we can detect with the naked eye even under ideal conditions on the earth's surface, until we get at least 30,000 feet up. Requires a knowledge of geometry and actual measurements of the earth to determine the curvature.
2. You never have to look down to see the horizon, no matter how hard you rise. If Earth were a real globe you’d have to look down
Not quite sure what this is trying to say.
3. If Earth really was a sphere hurtling through space, the water would be wobbling all over the place, instead of staying flat.
It is; it called tides, waves, currents, etc. It only appears to be flat.
4. If Earth really was a globe, rivers such as the Mississipi would have to flow uphill to reach the sea – flowing uphill 11 miles in its 3,000-mile length.
I assume he believes gravity exists, since nothing goes flying up into the air without a push of some sort. Gravity causes the earth's surface to curve to make earth a sphere, but if you don't understand geometry, geology and geography, then it's going to be difficult to explain that rivers flow downhill in relation to the distance to the center of the earth's mass.
5. If Earth really was flat, helicopters would be able to hover in place and wait for their destinations to come to them.
You mean, was really round.
While sitting on the earth before takeoff, helicopters are moving with the same rotational velocity as the earth; they do not lose that velocity when they lift off vertically, so they will maintain their position over the same location.
6. The railway from London to Liverpool is 180 miles long. If Earth really was a globe, it should be 5,400 feet high over Birmingham.
No, it should be 5,400 feet high over London.
7. If Earth really was a globe, airline pilots would constantly have to adjust their controls so as not to fly off into space.
And yet they don't have to keep adjusting their controls so as to not fly off into space. or else all pilots are actually in on the conspiracy and therefore lie about it.
8. If there actually were billions of stars in the night sky (Flat Earthers think there aren’t), the entire sky would be full of light.
Most of them are too dim to see as our eyes are not sufficiently sensitive. many are behind the ones we can see in the plane of the Milky Way, and most are obscured by gas and dust in interstellar space.
9. If Earth was constantly spinning, aeroplanes would never be able to reach their destinations due to the 500mph headwind.
Does he really say "aeroplanes?" Really? "Oh, mater, no more buttered scones for me! I'm off to fly a bloody aeroplane!"
Variation on #5. There are no 500 mph headwinds measured, because the atmosphere tends to move along with the rotation of the earth. Not sure where he gets this figure because the rotational speed is about 1,000 mph at the equator eastward, and are not significantly slower than that at the mid-latitudes; and the winds vary slightly around that total speed of rotation.
Since jets are able to fly at at least 600 mph, they would make 100 mph against the headwind, and would make 1,100 mph with the tailwind (as his logic seems to suggest). This wind would also affect helicopters rising vertically and bullets being shot straight up. And yet we do not see this effect...because everything on the surface and in the air is moving at roughly the same speed.
10. If Earth really is spinning, bullets fired upwards would land hundreds of feet Westwards. They don’t.
Variation on #5. Bullets are co-moving with the rotation of the earth at all times.
