first things first...ditch the test strips as your main way to test your water...test strips are fine for a "quick and dirty" check to make sure you have chlorine in the water before a soak, but for balancing the rest of your parameters (alk, calcium, pH) you want accuracy and strips do not provide that...Taylor K2006 is a good drop test kit for a fair price and is a MUST for new spa owners imo...
MPS/shock is more of a skin irritant that chlorine could ever be...this could be the cause of your wife's itchy skin/eyes, I also have sensitive skin and only shock once a week
if your pH is consistently "creeping high" than your Alk. is too high....Alk. is a pH buffer so Alk. must be proper (75-100ish) to prevent pH creep..again you will need a good test kit to get baseline numbers so you will know how to adjust accordingly
I wouldn't use any of the "non-chlorine" "chemical free" "all in one" or whatever fancy marketing terms you want to use systems, certain ones are ok in certain instances but remember there is only 4 EPA approved systems to maintain a spa...chlorine, bromine, baqua spa, silver ion/mps anything else is just to get your $ because in the end you will use one or more of the above with it anyways, so save yourself the $