I will try to answer first part of your question.
My understanding is that we are told in Quran, in various verses, a fraction of the conversations between Allah and angels and iblis, during the creation of the first human(s). I mean, Quran tells some of the things -which are important for us to know-, but possibly not all the things that was said at that time (what angels know, what iblis knows etc.).
As you also quoted, iblis asks time from Allah in verse 15:36, saying something along the lines of "until the day they will be resurrected". Based on the wording in this verse, at that time of speaking, iblis seems to know that humans will be resurrected (but the information about when the resurrection day will happen belongs only to Allah, verse 31:34).
Just before the above mentioned verse where iblis asks for time, in verses 15:34 and 15:35, Allah says to iblis, as I understand, "this curse (iblis being expelled from where it was) will be upon you (iblis), until the day of judgment/recompense (day of resurrection)". So, if you read 15:34-35, then read 15:36, it makes sense to think that iblis does know, at that time of speaking, that there will be a day of judgment for the humans, in which humans will be resurrected and judged based on their deeds.