Info on Irvine, CA?

I'm trying to get a broader view of Irvine, CA as a whole; if anything understanding. I see that the Irvine Company basically owns everything, and reviews are all over the place. I see things about the company giving positive reviews to make them look good - is this true & are they really that horrible? I don't understand brush fires and earthquakes - do they happen often? I've visted LA before a few times, but nothing extensive. I was told that quakes happen all the time, but you really don't feel them - true? Brush fires - why & what? Is there any additional insurance that I'll need besides renters insurance to cover this? Within the apartment complexes the walls are thin & parking is scarce for visitors? Is there any culture available within Irvine or will I have to travel to LA? Maps say that LA is pretty much 20-40 mins. away from Irvine? I might be moving there so I'm doing research.