I wouldn't worry about the winter since the colder water temperature will naturally have the pH move upward, all else equal (so let the pH drift up on its own to 7.6 or so during the winter). As for the summer numbers, the roughly -0.2 saturation index is fine since you don't want scaling in the salt cell where one plate is at high pH. Since you are using borates and keeping a lower TA to avoid the rate of pH rise (I assume), you have a higher than average CH to compensate. This all looks good.

Richard