Yes, LA is totally livable.
Though it depends what you mean by "livable," really. I'd heard that LA was less a city and more a collection of towns--a sort of never-ending sprawl with the occasional town center. The downside to that is that, traffic being what it is, once you're in a place, you might stick there. So, you leave on the east side but your friend is having an awesome barbecue on the beach at Santa Monica... chances are you're not going. I mean, you could if you wanted to--if you had to. But you probably won't.
Or as one friend put it, when he visited, he went out every night and saw people and it was super social; and then he moved there and he hasn't seen anyone since.
So, while there's probably a lot going on and a lot of scenesterism (i.e., you have to go to this bar, it's where everyone goes, there's no parking, but you'll get a valet, it'll be fine), there's probably also a bit of homebodyism, too. Or at least close-to-homebodyism, where you stay around your home or you stay in a certain area or in a well-trodden path.
It's basically like that one story in Italo Calvino's Invisible Cities, where everyone sticks so closely to a certain repeated path of life that they can spin these different cities off into their own cities, thus relieving congestion.
Which brings me to the worst and most easily managed part of LA: the traffic. It is terrible. Not always--there were times when I zipped along the freeway pretty easily. Then there were times when I was stuck on a city street for a long time. You can see how people, shuttling between this feast and famine condition, would grow a little harried and shitty as drivers. And you do have to watch out for drivers being shitty drivers. Not evil--just incompetent, short-sighted, with blinders on. Thank god I was driving a newer rental car and not my 18-year-old Honda.
But here's the mantra: this too shall pass. I was stuck in one spot for five to ten to fifteen minutes--the worst traffic I've ever seen, and I've driven in New York, Boston, and London. And eventually, I moved.
The other mantra for driving in LA: some time, some one will realize this is their exit and will need to cross three lanes to get it; and some time, that some one will be you. So treat others as you wish to be treated on the freeway.
So, yes, with the terrible traffic, there is a chance that you might move to LA and discover that you aren't always up for gallivanting around the city to some improv show (probably sold out, plan in advance) or to some dinner party (though you want to go because there's a guy there who works for Laika and you want to make that contact). Sometimes you will be not in the mood to take advantage of the advantages offered by this advantage-stuffed city.
But at other times, you will be--and then it's good to have those advantages at your fingertips.
In short: LA is very livable.
In slightly less short: I'm not sure when or even if I'll be moving there, but I'll be perfectly happy to give it a chance.
And I may even take one of those "learn a foreign language in your car" courses with me. Sehr gut? Çe n'est pas mal.