hmm, your last pic doesn't look so bad, i think it has improved a bit
good chance there was some root burn, that takes some time to recover
for other grows that 'rode out' the burn from a nuted soil, plant kind of holds on until it can tolerate the high nute environment. i think you may have turned a corner. just my guess, not a fact
on the mold, it does look like mold - not a mold expert, haven't dealt with it before
a light scraping of the affected soil should help some, replace with fresh soil
maybe a bit of h2o2 might help, not certain on that i'm afraid, you may hae to do some searching on mold