Yep... Therein lies both the reward and frustration with Wet Shaving... Details matter and you may be shaving with the best edge one moment and make a ridiculous yet critical error the next and have to start over. This happens occasionally with nearly every stage: Lather, Skin Prep, Skin Stretching, Angles, Pressre, Stropping, etc. But, this is most frustrating with Honing as it often truly mean you absolutely and literally must start over. That is why so many recommend just waiting on the Honing.

I can tell you are reading and watching Videos and you are scratching at the surface for sure with the Honing Info and Questions. But, setting up Stones, Film or Media to Hone is completely individual and completely different from one another. What you are asking about (Refresh Stone & Coarse Stone) is a multiple stone/grit progression. But, as a comparison, with some Japanese Natural Stones you use varied coarseness Nagura (Prep-Stones) as you move through a progression but the Base Stone/Japanese Natural is used from start to finish and you mix grit from the base stone with the nagura or other similar stones.... More Art Form than followed recipe.

Easiest thing to do is start a savings for stones and give it some time... You will know when you are ready as it will simply be the next thing you are ready to try due to being so good with the other aspects of wet shaving.

Shave-Test is the only consistent (... though nealy wholly subjective as well...) Test you should focus on as the other Tests are moreso used to help refine honing direction. Most important thing, if you do get something honed by another person, is to just wipe any oil/protectant away then shave as normal to give you a benchmark for what their "Shave Ready" feels like to you... Don't Strop, Test or anything until you get that First Shave done as that alone will tell yiu when it is time to go back for a re-hone.

Edge Quality and how long it lasts depends on many factors. I have shaved with the same razor for 18 months now and have done 2 Refreshes on it in that time. One was because I got a New Stone and wanted to try it and the other was me noticing the edge dropping off. Even that all depends on various factors as I only shave a couple times per week whereas someone else may be daily.