Polar launches aren't very useful for most things. I think the populations of CA and NV would also object to boosters being dropped on them.
Due to the Earth's rotation, it's most useful to launch to the east, over water. The ideal location is on the equator, and that's what Sea Launch does, sailing out to the middle of the Pacific at 0 latitude to launch rockets and get max payload for the minimum thrust.
As for storm damage, not much. It's all built to take hurricanes, so only tornados do anything. There have been numerous delays due to weather, but more due to over-cautiousness than anything else.
If the shuttle had to abort back to KSC (something that was considered highly dangerous if necessary), the winds at the SLF couldn't be past a certain amount cross-wind (I don't recall the number). If a rocket explodes at low altitude (a few thousand feet) when the wind off the ocean is blowing a certain way and colliding with wind blowing from the west overland (which causes the storms on the east coast regularly, oddly it doesn't really happen on the west coast) there is risk of a cloud of deadly chemicals blowing over Merritt Island and killing thousands.
On the flip side, I'd hate to see an earthquake hit as a launch was just prepping when all the gantries have swung back!