Definitely give you box of cal hypo to someone you don't like.
You can vacuum up the flakes, no worries. Do you have some kind of automatic cleaner? Robot? Use whatever is easiest. The filter will catch the flakes and next time you clean the filter they'll get flushed out.
As I said earlier, I'm going to "put my money on the black" to coin a Vegas phrase - I really think the acid injector location is the source of your degraded IC's and so, yes, I think your IC60 has been impacted. When my previous IC-40 started to spit snowflakes after 5 years, I got another 3 years out of it. So it will probably still work for a while, just be prepared to replace it.
Don't use ANY shock products. If you need to raise your FC to shock levels, use liquid chlorine.
650ppm CH is not great. If you can't lower your CH easily, then your TA and pH need to be lower. You need to target a negative CSI value, anywhere between -0.3 and 0, preferably hanging out at -0.1 as much as you can. This will likely mean keeping your TA below 80ppm, and making sure your pH stays around 7.6.
Questions are what we do here at TFP, ask away ...