I need anyone and everyone’s advice.

I happened upon http://www.escapistmagazine.com/articles/view/columns/criticalintel/10056-Desperate-Housewives-of-Skyrim?utm_source=latest&utm_medium=index_carousel&utm_campaign=all on The Escapist and it reminded me of one of my more common marriage choices, Aela the Huntress.

It breaks my heart to have tied Aela the Huntress down like she becomes.
I’d like to take her out on my adventures but couldn't stand it if she died.
Instead, I unwittingly turned one of the game’s most badass females into, as the linked article said, a vending machine.
This is why I’m confused that Serena couldn't be married. She doesn't like temples, sure. So let’s get married at the Castle! Something! Anything! She’s so much more interesting and is marked essential so I won’t have to worry about her health.

How can I play a game wherein I can take my spouses out and they won’t immediately die?