What may be causing leaf damage? And would I get the ph down in living soil by going negative to get to the ph I need to be at

yes, you can ph-balance it by adding slightly more acidic water. Be aware that the "middle" is not tthe middle point because pH is a log scale base 10. Seven is "0", conceptually or equal parts proton donators (acids) and acceptors (bases) canceling each other out. So, don't go too far below where you want it, because 7.46 isn't to alkaline to start. Start with 5.5-6ph while checking it as you go. living soil will always be a seemingly high EC. (TDS pens don't measure ppm or ppt, they convert from EC and it's totally inaccurate. there are 4 or 5 conversion factors that are whimsically used be various manufacturers, i.e. whimsical chioce = not acurate or precise). It is consistent though, and that can be a useful tool with time and familiarity... when times are good, learn that baseline EC/ppt readings and that's your target in future. 1000-1800 ppm (just multiplying by 10^3 to convert, shift decimal 3 spots right) is probably fine for living soil, but the ratios are the likely adjustments you need to make - somethign you can't really do midstream with living soil. you'll have to constitute it / amend it differently next time. hopefully supplemental fertilizer can even it out. More perlite... with a heavy soil you want 50% perlite or similar. Vermiculite #3 is a great option too. Looks like a bad ratio of nutes and probably a releasing a bit too fast causing a hot soil. This is about how the soil was built.