Hey Tom - I've got the just superceded model.
I have three kids - 11mths, 7 yo and 9 yo.
My two oldest don't need booster seats or a H harness so we've got it a bit easier than you.
As you know, the middle row anchor points are in the roof at the tailgate. When our baby seat is in the middle row drivers side, the third row is still quite usable. The strap is 'in-your-face' a bit but OK as long as the person isn't too tall or claustrophobic.... When it's in the middle there's a bit of an access issue to get to the far seat but again still mostly ok.
You are going to have a problem with having all points in use if you want to put 2 adults in the third row.
What config where you going to run with?
I'd run with baby seat on drivers side, H harness in centre, booster seat on pax side.
You could swap the booster and H around but I think either way, to get to the back row the booster seat would have to come out while loading up.
If you were wanting to carry your family plus two adults I'd put booster plus one adult in third row and baby, H and adult in the middle.
Back to your Qs
a)Yes can be done.
b)Yes (!) if all 3 are in use in the middle row but there are ways around (as above)
c)Use of 3rd row anchor makes it harder to use the luggage space and will restrict what you can get in there easily. Shopping bags - no dramas but a pram?? Stroller would be better bet!
Don't know where you are but if you are going to spend $50k on a new car find a dealer who will let you take in your whole family, car seats, pram and all, and do a full reality check before you sign up. I did for mine and I'm glad I did.