So no pink for the second part of the test means you have no Combined Chlorine (CC) and that's good.

Good catch on reading the wrong scale. Sorry I didn't think of that. 50 ppm CYA is fine and just means you should have from 3-6 ppm FC in your pool (I'd try and target closer to 6 ppm).

As for auto-dispensing chlorine slowly and automatically, that's tough since Trichlor is the most convenient for this purpose, other than a saltwater chlorine generator (SWG), but unforutnately Trichlor will increase CYA levels. Having used Trichlor in your Hayward chlorine dispenser means you cannot use any other source of chlorine (i.e. no hypochlorite source such as Cal-Hypo) in that dispenser -- ever. There are slow dissolving Cal-Hypo tablets and those are an option for you in some sort of floating dispenser, but they don't dissolve as cleanly as Trichlor. Cal-Hypo also adds to Calcium Hardness (CH), but that is not a problem for your pool since it's vinyl and your CH is already low so adding more, at least for a while, should be OK until you get to around 300-400 ppm or so. If you are gone only now and then, perhaps you can use chlorinating liquid or bleach while you are around (adding it directly to the pool slowly either over a return or into the skimmer with the pump running) and when you are away turn on the Hayward with Trichlor.

Perhaps someone else has a suggestion for what you can do more "automatically". You can, of course, continue to use Trichlor (especially when you are away), but should either drain/refill your water to keep the CYA level low or if the CYA goes up, then you'll need to increase your Free Chlorine (FC) level according to this chart.

The store product that is equivalent to "pH Up" in pool stores and is simply sodium carbonate is "Arm & Hammer Super Washing Soda" as seen here.

Richard