Rick in the USA.

For number one, I would go with a train. At least for as much of it as you can. Much better than going on a bus. As far as what to take, I had to google for is. There's probably other ways, but one way is to take the Amtrak from LAX to Solana Beach (SOL), which is about a 2 hour ride (36 USD). From there, you can take a bus to UCSD. Someone who's been around LA/SD with public transport can probably give better directions. http://www.amtrak.com

Also, keep this handy for travelling within SD: http://www.transit.511sd.com/

Also I found this, which may or may not be helpful: http://www-ogsr.ucsd.edu/about/welcome/t...-ucsd.html