More answers / clarifications, thanks for asking!
Sorry, being a bit vague here since it’s not all designed yet. You will certainly be able to craft gear, with lots of cross profession crafting where it’s natural. Blacksmiths’ crafting mining picks and needles for tailoring for instance.
We’re excited for this kind of cross profession interaction, particularly because it means someone could choose to be more of a supporter within their profession, specializing in crafting gear for various professions, reagents for others of their profession, etc. (depending on the profession)
Gear will definitely be a big source of these stats. Certain choices within your profession specialization will also allow you to gain some of these profession stats.
There will likely be other sources as well…enchants, consumables, etc.
Being inspired (and gaining the bonus skill) is RNG based on your Inspiration stat. More Inspiration = higher chance it occurs, similar to more Crit = higher chancing of critting. But as mentioned above, there are lots of ways to opt into gaining the Inspiration stat if you want it.
Sorry, in general I just wanted to note that optional reagents can raise or lower difficulty, depending on their effect on the recipe.
The example I mentioned above would be if we made an optional reagent like the Novice Crafter’s Mark from Shadowlands, which lowers the required level from 60 to 50, and lowers the item level from 151 to 87.
Just to be clear though, the introduction of quality along with profession stats is for Dragonflight recipes specifically, I’m just using Novice Crafter’s Mark to illustrate an example of the type of optional reagent that might lower difficulty.