I've never used Red Sea test kits. 'Looks like it has a lot of stuff.
Only occasionally, and during the nitrogen cycle, you need to test for Ammonia, Nitrite, and Nitrate.
More frequently, you need to test Calcium, Alkalinity, pH, and Salinity. I use Aquarium Pharmaceuticals for Ca and Alk, a PinPoint pH monitor for pH, and a Captive Purity refractometer for salinity (although floating glass hydrometers are accurate as well).
Salifert makes very good test kits, although they're a little pricey. Regardless, for pH, the color chart tests are poor - best bet is a monitor.
You may want to consider a Magnesium test. I only test in response to Calcium issues (trouble rainsing/maintaining) and to know how to dose saltwater used for changes).
Posphate (PO4) is a good-to-have test, but is also used more rarely.