Regardless of what you read, in my experience Horticultural grade rockwool is pretty much inert. I rinse it off before use but I don't use any special treatments on it and I've never had a problem.

I've never used Sphagnum moss but i would be concerned that it would start to decompose and clog pumps and drip emitters (if applicable).

Generally in hydroponics the pH and nutrients are adjusted seperately. You can increase your nutrient concentration without throwing the pH way off and likewise you can adjust pH without adding nutrients. You should be able to use just about any nutrient with any growing media without major modification.

I still soak my rockwool overnight just to be safe, but I'm probably overly cautious.

The only thing I know of that benefits from a specially-tailored nutrient program is coco coir. Many companies make a nutrient line especially for that. Something to do with the special nature of coco, which unlike most hydroponic media, actually has some nutritional value in it or something like that.

Even so you can definitely do fine growing in coco with regular nutrients.

Basically it depends less on the media than on the nutrients. Use high quality stuff and you're going to get more consistent, reliable results. Cut corners and your plants will show it.

I've never really had a problem with Advanced Nutrients, which is not something I can say of anything else I've tried. That's my advice, anyway.