For your routes... UA is probably the best avenue for you... You could match to CO to preserve your one-time UA status match... UA has nonstop flights out of LAX to all destinations you listed, except for Seoul. However, UA's Star Alliance partner Asiana flies nonstop to Seoul or you can do a short hop up to SFO and connect onto the UA SFO-ICN flight.
You can still keep AS as your secondary program.