Welcome Philip, 6 months will fly by!
Air, I have it on 19's maybe not essential, even with 20's, but we love a smooth ride. I had a day out in the back of a PASM only Macan earlier this year and thought it was a very poor ride with 4 up, so convinced we made the right choice.
Spare wheel - well worth it for convenience, and not expensive on a new build. I bought one for my 1st Macan (an ex demo car), and paid £500 - ouch! Its now in Macan No 2, but when I had my puncture last month, 450 miles from Calais, there was no point in using it, car on transporter courtesy of Porsche breakdown and a new tyre.
PEC, not sure you will be able to check out all your spec options, it will depend on what cars are available. I concentrated on the driving - a GTS - and found it invaluable.
Factory collect? not done it but others were doing so when I went on a factory tour in May (in my new Macan), mostly Americans collecting their 911s while Stuttgart was closed. You will really enjoy the fuss they make of you, so do so if possible. There is a well stocked shop, a bit of a museum and as part f the follection you'll have the tour and (I think) a track session plus some very good food. I stayed in the budget hotel on the Porsche list just a mile or two from the factory, more than adequate. Perhaps take in Mohne Dam on the way home and Colditz Castle (if WW2 is your thing) for a day out in your new Macan.