I don't really want to start a debate here, but there is much debate on the validity of the SRM values being used in the water spreadsheets as they over simplify a very complex relationship and make some assumptions to use that formula that may not be appropriate for some beers.
Your Carafa counts as a roasted malt, so in theory it should help lower the PH for the duration of its contact with the mash, though probably not by much if you're just adding some color with an ounce or two. I would not use it in your calculations to set the PH. What I would suggest, is that you add the carafa after you run off, then when you add your sparge throw it in as your sparge water will raise the pH of the mash so the carafa will add color you want and help a little with keeping PH in check (though its contribution will be minimal with only an ounce or so in the grain bill).
I wish I could comment in depth on your hardness, but I am not a water expert, only started diving into it recently. From what I know, your hardness is a little higher than what you would want to start with as you'll be raising that number with your salt additions. I am pretty sure that Ajdelange would recomend that you cut this water with some RO to get it down to an appropriate level. Based on what I know, it looks like you could get to reasonable alkalinity levels by using 50-60% RO water. AJ may chime in here and give you more advice that is more meaningful on the Alkalinity component.