What type of calcium, alk, and magnesium supplement did you pick up?
That's great to hear that your alk has increased. You really shouldn't need to dose Ca at all, you were already above the recommended value.
For nitrate, do you mean 10 ppm, down from my 22 ppm? Btw, if RCA tested it for you, they use API which I find highly inaccurate too. I trust it to tell me if I'm high or low but not for an actual concentration. But from your water changes, you're probably at least at a ballpark around 10-15 ppm so it should be much improved already.
While normally I wouldn't suggest adding any corals until the water parameters get in line, they must be doing fine for now if you haven't mentioned any detoriating conditions.
Keep an eye on the anemone. He's getting too dangerously close to the MP-40 for my likes.
Everything else looks good. Just monitor the new additions and look for polyp extension as well signs of distress.