Detailed nepenthes problem showcase

[DanyR]

Thanks Strath, I now feel a bit more reassured, I thought it was something more serious, but i'm going to start the work on the stuff you mentioned.
About the small black and red dots on the back of leaf, don't you think its some kind of insect creating them ( mites maybe, not sure... ) and if yes, is the active ingredient that is present in the insecticide that i used harmful ?