Take it from someone who plays in mostly rabbit hole-less worlds, the game will not bug and your townie Sims will not die.
However, I wouldn't suggest leaping into this type of game-play blindly. Unless you want to test how well you can handle Sim emergencies. The game will throw curve balls at you left, right and sideways just to keep you on your toes. Rabbit hole-less worlds require you to put in the work otherwise it will become a huge headache before you even get started.
If I were you, I would do a little pre-planning. If you are going to have animals enabled in your game. Strays will also need to be looked out for, this includes deers. The first time I removed needed food sources from the animal population, they all came to my Sims front door with the starving image in their thought bubbles, so I had to fix that quick.
Also, things from the grocery store such as eggs (if you don't own the chicken coop), tofu and all meats can be grown via the Omni plant. So plop a few of them down, feed it and harvest them the next day.
You will also have to give your townie Sims a little time to adjust to the changes of the way things work. Socialization will be heightened so have community lots with things that will engage them while you work it out.
When it comes to sickness, some cures can be found in the herbs (University Life), for other things the moodlet manager (Base game lifetime wish reward) can help. Knowing which herbs to keep plentiful is a must. Also, if you have Supernatural installed, don't overlook the importance of the elixirs.
If your concern is having the townies work, you can always set up your own places of employment for them. And, you can always use the rabbit hole replacement rugs if you still want to keep the opportunities and special events happening.
However you choose to play, I hope you find your new game entertaining, rewarding and Sim enlightening. Enjoy!
Hope this helps :)!