Ok Dorje, what are the signs for overwatering, and what are his indicators of ph issues? And what's the difference in appearance between the two?

Soil meters are 100% unreliable crap. Unless you are either replenishing used soil and looking for a ballpark figure, or if you are mixing your own. Most quality potting mixes are pre-buffered, so will show no changes till buffers fade. You'll want to keep your water from fighting the buffers, and only knowing soil ph won't help there.