Earth is slightly pear shaped.

This has no significant effects other than the orbits of satellites. It
doesn't cause any daily or seasonal changes which affect life on earth.

Earth wobbles on it's axis.

One wobble takes 26-thousand years. This too has no effect on the
seasons or climate. It just changes the direction that the earth's axis
points towards in space.

Earth is gradually slowing down, that is why we sometimes add one second
to the lenght of the year.

This is caused by the tidal (gravitational) interaction of the earth and
moon. The earth's rotation is slowing down and the moon is moving
farther away from the earth in it's orbit.

The solar system which Earth is in which is also in the Milky Way Galaxie
is moving through Space at about 60,000 miles per hour.

It's all relative. The earth is moving (rotating) at 1000-miles per hour
at the equator. The earth revolves at about 66,000-mph in it's orbit
around the sun. The solar system is revolving around the center of the
galaxy at about 550,000-mph. Our Milky Way galaxy is moving through
space at millions of miles per hour relative to most other galaxies but
we are actually approaching the Andromeda galaxy, which is currently
about 2-million light years away. (11,600,000-trillion miles) It will
still take about 3-billion years before the big collison.

http://tinyurl.com/2zlp44

Earth is closer to the Sun in Winter and further away from the Sun
in Summer.

This is true only for the northern hemisphere and it's not what causes
the seasons.