Spot plaster?? It's not like it's drywall getting patched. Making a repair will definitely be noticeable especially on any colored plaster. I've posted countless times on this thread about plaster issues and to reiterate, it all starts at the beginning with a proper prep, to weather conditions, application, filling and chemical care. If any of these,and some in between not mentioned, are not strictly followed, there will be a failure in the finish. The contractor should have been prepared with a tent before the rain. Carefully checking and monitoring weather prior to working pays off. The white spots may be calcium nodules. In pool plaster, it generally indicates an improper bond of the plaster to the substrate (original plaster). Mostly seen on re-plaster jobs and not new pools. Re-plastering requires a bond coat to allow the old and the new plaster properly bond. The problem will persist and probably won't go away. Acid washing might help a bit but can etch the surface making it rough. And who wants a rough surface on their feet? Here's a good explanation on this subject. https://www.troublefreepool.com/threads/calcium-nodules-in-pools.66499/#:~:text=What%20are%20calcium%20nodules%3F%20In%20swimming%20pools%20and,rough%20to%20the%20touch%2C%20hard%2C%20and%20generally%20gritty.

Hmm, it never was as dark as you describe, are you diligently brushing and such? I do remember it had a true gray quality at first, but never black in nature, so that part does confuse me. I can say that ours lightens appreciably when we are low in acid and darkens when the acid load is correct (we like the darker look). We have VERY hard water and use a salt system. I'm not sure I'm much help, sorry! My main advice for now is to brush daily per the recommendations and then wait for chemicals. I'll see if I can dig up some first day photos, we're a few years out now, but they are around here somewhere!

The height change is because there are two distinct deck surfaces, one on top of the other. Like you said, its gone. The coping is toast but can be replaced. This often gets you some chipped tile. The finish is a delaminating Diamond Brite. It will need removal and replacement with a new plastering finish, whatever finish you choose, be it plaster, colored plaster, and the varying levels of higher aggregate finishes that are available. Given the coping and plaster are toast, I would strongly urge the tile go too. The shell seems OK. Is there copper plumbing? If so, replace it. Since the deck is going, adding a bond wire to the shell, light, ladder cups, and equipment pad should be done. In terms of work, it's not that big a cost. What equipment is there for the pump and filter? Scott

I recently had my 34 yr old gunite pool re-done with Luna Quartz, it looks GREAT! I had my pool deck re-done last fall so the entire area looks brand new - BUT, now the one jet I have in the shallow end of the pool (where the kids like to hang in front of the heated water) has a piece of white plaster preventing 90% of the water from flowing. We had the white marlite removed prior to the quartz finish put on. In all our years of owning this pool that jet as worked fine - now my pool restoration company refuses to own what they did and tells me that they snaked the entire system and found no blockages (total BS) - you can feel and see the plaster about 3" into the jet, how can I remove this??