30C can cause problems particularly if humidity is really low as well (below 25%). It's not much over the general 85 degree cap for most strains but it can be enough to delay flowering time. Do you have a
pic of what you use to test your temperatures and humidity? You might also notice new growth on the lower branches forming with a longer branch or filament, making it look
almost like an early male flower. Again, this can be subtle and is respective to the ambient environment. The pics provided really didn't offer adequate perspective. If you're concerned with the leaves you should take a picture of the
leaves rather then a general profile of the plant. Plants leaves don't usually curl under
like that from a deficiency -
Toxicity absolutely. A full on nute lockout though can cause problems like that - if salt is in excess leading to less water retention by the plant in the rhizosphere ergo the whole plant. This might explain the blotches on your other leaves but it's hard to be sure. Did you flush before starting your flowering nutes? What is your grow medium? Watering schedule? I understand that you say that you are following a strict feeding regime but you should understand, that this is a forum and anyone can lie about anything so the more details and pics the better. Also, can we have your mailng address. Full name? Social Security #? Lol j/k about those last three. Or am I?