... For example: should I think about changing the carburetor, any brake upgrades, changing suspension (I would like to hit some mild/moderate trails some day) or should I just drive it until something goes around and change it then. Everything is working fine now, but when things go wrong it's always at the worst time, those are the things I'm trying to avoid.
Short of re-doing the entire Jeep, you'll never be able to fix everything before it breaks.
If you have the standard front disk and rear drum, I don't see any need to upgrade the brakes for a daily driver or basic trail Jeep. The factory brakes were fine then and should be fine now. Just make sure that the brake system works correctly and is maintained.
As far as suspension upgrades? None needed. Again, if you're primarily concerned with the Jeep as a daily driver, the stock suspension is fine as long as it's in good shape. The leaf springs will sag over time so you may want to check that, but otherwise you should be OK.
Keep in mind that running the Jeep on mild to moderate trails is probably what AMC had in mind when they designed her. As long as you use your head on the trail, you should be fine even in a stock Jeep.
As far as replacing the carburetor, well, sure, that's an option. How much time and money do you want to sink into the project? Is the stock Carter BBD giving you problems that you're tired of dealing with? Remember that it was/is typical for carburetors to need service and/or rebuilding every 30,000 miles which is something that most people today don't realize. That's a vastly different paradigm than today's fuel injection engines that will run for a quarter of a million miles with very little trouble.