Nancy ... I've never done a mystery, but I've completed a lot of quilts and can (or can't) help with some of your questions.
The clues post weekly - from Bonnie's site "Our first clue goes live on Friday, November 28th, with each new clue being released on consecutive Fridays until we are complete. Plan on 6 to 8 clues – I haven’t decided how to break it down yet. Remember, it’s a mystery for a reason and some things need to be revealed without us knowing every detail first!"
She further states that it is very likely you will not complete everything you need to do within the week before the next clue is released, but to put the project aside and start the next clue anyway. That way you will be ready to follow subsequent clues. And remember to print all of the clues for yourself as they WILL be removed from the site at some point. Don't expect to finish all the cutting and sewing from one clue to the next would be my best advice. Plan on having some of them done and those along with your printed directions are your reference to finish the remainder on your own time after all the clues are posted.
Being a mystery, it's impossible to tell at this juncture how much time it will take without knowing how many pieces, size of pieces, construction (i.e. are there Y seams? (probably not!)), etc. We only know that there are 6 main colors which is quite a few - so I'm assuming the block will be fairly complicated (i.e. many pieces), and there is probably a sashing (just guessing from the black and neutrals). My assumptions are also based on some of Bonnie's other patterns where many colors were used.
I've never used Inklingo so can't help yo with that one.