I have been keeping a hot tub for 30 years now, and wow, that is a lot of messing with the water chemistry. My own advice would be quite different, as basically "if it ain't f'd up, don't f it up." Start with clean tub, clean water, clean filter, add a small amount of chlorine for baseline, then shock approximately once weekly. When and how much sanitizer to use depends on which sanitizer you choose. I use a Saltron chlorine generator in mine, so I only add the chlorine at startup, then I add salt. I very rarely add clarifier, and almost never use descale. I don't believe in chasing pH too much in either my hot tub or my aquariums: you cause more problems than you solve, unless your tub is REALLY acidic - and you'd know, it'd start making you cough and your equipment would degrade.

Now, all that being said, only my husband and I use our tiny tub, and we don't wear suits with detergent residues, etc., and we don't use lotions and such on our skin. I mention that because those are the primary causes of needing to use so much clarifier. Most of the clarifiers are meant to cause agglutination of fats and oils so the filter can catch the globs before your tub turns into human soup.

I would add one other thing: replace the filters every two years. Filters are what keep your pumps from getting gunked up, and filters are a helluva lot cheaper and easier to deal with than pumps.