Hey Squee, not that it matters, but i notice you always do this. And I'm only saying this because someone asked me if my name was a typo, but it is suppose to be new-e-user! lol, you always put newuser! it's ok, i'll take it as a nickname!
"if you've got something to say, say it peacefully"
Here is a different diagram using two switches and it's pretty simple. The diode pack is just 6 diodes in series to drop about 4v so the fan will be safer. The switches only need to handle no more than 3-5A, so they should be fine - they aren't carrying high currents.