I'd get a handle on figuring-out a good watering schedule before messing with the ph too much more. But I'd keep all ingoing water twords the higher end of the acceptable ph range. I'd work on the watering/feeding thing first though. Never cut-out feeding days, but watering days should remain flexible.

The spots I can see (that's one tiny picture) look like they could be man-made. Did you squish the leaf between your thumb and the pot at some point? (when picking it up, for instance) Could be leaftip irritation from the plant next to it rubbing back-n-forth across the surface, too. (if applicable)

The first 1/8" of leaftip I volunteer to the leaftip gods, as it turning brown or yellow is rarely a sign of anything worrysome. If the neckrosis goes up any further than that, then worry.