I agree, i have just come back from LA, usually go there many times a year.

I would do the drive mid to late morning as that is probably when the traffic is not so bad. You could take the I 405 or the I 5 to LA or the PCH (pacific coast highway) if you want scenery! Its very nice drive along there.

You want to arrive in LA around 2pm before its starts going mad again!

The drive takes two to three hours depending on traffic

Three hours for transfer at LA should be enough but it can be busy at immigration. If you are a US resident, it will probably be faster as the residents queues sometimes are shorter than the visitors.

More often than not the bags have been on the belt before i have cleared immigration and its been straight through customs etc