The most practical way to know if your dose is right is to get your uric acid tested after a few weeks on that dose.
Also, you won’t know if your liver and so forth are fine until you get bloodwork for them AFTER you’ve been a while on puricos.
Whether you will need to be on puricos for life also depends on your uric acid test results. If obesity was the reason you had so much uric acid for instance, you might be able to lose the puricos once you lose enough weight. But that’s certainly not a given. Time will tell.
I doubt probiotic has anything to do with puricos. But if you heard differently, I’d be interested to know what you were told.
Lots of “natural” things bring down uric acid. But unless you get side effect from puricos, I would recommend sticking to it because it’s cheap, works better and you can also get side effects from the “natural” things.