This is the only part I don't understand. Can you explain how to keep the card active? It isn't simply purchasing something anywhere, you have to do it through Southwest?
Exactly what PP Suyami described. Once the points are credit to your SW rapid rewards account, you have to have some sort of activity within two years to avoid the points expiring. The activity could be buying points, transferring points, buying a flight, anything that adds/subtracts points to the account. If you have cancelled the card you won't be creating "activity" that way, so like many cards, SW has shopping portal that you can go through to make a small purchase to add some points to your account and add another two years of potential inactivity time to your account. You don't have to use your SW Visa to make the purchase, but be aware that if the bonus points don't post correctly or at all, it will be difficult for Cartera (the portal admins) to track your purchase. This has happened to me a couple times.

It's just that fine print says you can't. Now for all those that will post saying they previously got it with two personal cards, I will respond now by saying this verbiage was evidently added from the previous offer that ran.