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.

IDK if this is pests anymore. Maybe pets.... Do you have a pet "cat, dog, bird, lizzard?" that likes to much on leaves? Sometimes I have found when I am over watering my plants the leaves grow in all weird and stupid because the roots are not getting enough air exchange aka oxygen and its causing defects in the new growth. This is what it looks like to me with the new pics. and the medium does look a bit to wet. Or something is chewing them or damageing them when they younger and this is the after math. PH of 6.96-7.46 is a bit on the high side. May want to try and lower that down to around 6.5-6.8, some PH down should work just fine. EC of 2.09-4.96 is a wide range. Means some plants are overfed and others are happy. I don't like to see my EC go above 3 tbh. but I have limited experience growing with liquid nutrients I use a lot of amendments. I think you need to manage the watering issues and things will start to come back to normal. With soil grows it works best if its water/feed/water/feed not feed feed feed like hydro setups. A bit of runoff always helps prevent buildup as well, but I find most soils hold onto way to much water and getting run off over saturates them and add issues. Let them dry out a bit more. add in more airflow into the tent or room they are in. and only give them PH'd water next time it is needed.