It seems rather counter-productive to me to add alkalinity in the form of chark or baking soda when we as brewers are trying to reduce alkalinity and thus reduce our mash pH.
It's only counterproductive if you are in fact trying to reduce the mash pH, which is by no means a universal condition. In the OP's situation, he's starting with a water that has no buffering potential at all. When he introduces crystal malt into the grist it will fairly quickly reduce the mash pH out of the desirable range, especially if he's adding calcium salts as you suggest. (And adding sulfate and/or chloride salts for flavor reasons is good advice, as long as it's in conjunction with maintaining the residual alkalinity at a reasonable level, but the OP said he doesn't have access to them at the moment.)
Since you mention Kai Troester, I used his water spreadsheet to work through this example. For a 12 SRM beer and an infusion ratio of 1.8 qt/lb, it estimates a DI mash pH of 5.40. Adding 50 ppm Ca reduces that to 5.35. In this particular case, that's narrowly within the optimum range (5.3-5.8), but it certainly illustrates the point. For a darker beer, adding calcium salts without also adding alkalinity would drop the mash pH out of the optimum range.
Edit: Had to disable the 8) smiley.