1. Is there an event or some possible way to check if there are any mining/herb nodes on the minimap?



    Nope, that information is not delivered on purpose.

    Alright, I also have another question,

    What is the best way to determine what piece of loot drops and who receives it?

    And is it also possible to record rolls that occur in the chat frame?


    You can find out what loot dropped by opening the loot window.. it can't be done other than that. You can determine what other people loot by checking the chat messages that appear in chat. Yes you can also determine what rolls were made.

    I mean in an addon, Im working on a loot addon.

    The addon needs to record rolls and loot

    Yes, I'm aware. You can do all of that in an addon, through the method I indicated.