SWA won't be able to move all that quickly. Any Int'l market they desire to move into will probably already have at least one carrier in it. The competition will be alerted well in advance. The history with SWA is to go into a city with many flights to many destinations. Use the re-entry into SFO or even RSW as a model.
SWA will have to change their system to accomodate assigned seating, countering their recent decision to stick with a modified cattle-call. This is a governement/immigration requirement. Personnel will have to be trained. And if you think you can turn an airplane in 30 minutes with ICE, you got another thing coming.
ETOPS is even harder to acquire than int'l ops. Look at Alaska. They've been working on it for a year and a half or more for limited ops. to HI. 180 minute ETOPS for the B737 is stupid. (Why hasn't Boeing put a RAT/HMG on these things?) Flying to HI with a -700 is insane. To get any kind of yield you need a larger airplane. The real money is hauling freight to HI from the mainland. Aloha has pretty much showed the limitations of the airplane. If GK pushes for HI/ETOPS with the -700 he should be fired.
The above limitations are not necessarily that difficult to learn for crews, but they can be screwed up readily by them. It'll take about a year to train the crews as they pass through recurrent. The difficulty lies in maintenance, dispatch, reservations, and operations, not to mention government sign-off of all the procedures.
SWA needs to develope new, high yield revenue streams. Their non-fuel costs are rather under control, so their's not much savings there. So the alternative is revenue enhancement. Domestic expansion vis merger/acquisition isn't the best path to that end.