It looks like you've been doing your research in the wrong places. See:
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/961029b.html
"the planets in our solar system -- aligned or not -- cannot cause a shift
in the movement of the Earth which will lead to mass destruction"
"the other planets in our solar system don't matter at all compared to the
Sun"'
"All the other planets in our solar system added together do not have as
large a gravitational effect on the Earth as the Moon does."