EP be mindful that the "just finishers" of Finks plan are probably going to be training much faster than you are and will probably "just finish" in around 13-14 hours or less I would guess (though I am happy to be proved wrong). I think realistically you will need to aim to do a bit more than that
As HC says its more about before than after (though it will be better if you don't have to race straight back to normal work) for both a full and a half.
The turbo will be fine As long as it is stable it is really quite hard to fall off it (though it has been done). You will get used to it. Just don't think about it and as you don't need to put your feet down during the work out it won't matter if you are six feet off the ground.