Not really. If you pick a reasonable estimate you'll be fine. Your maintenance calories usually sit between bodyweight in lbs x 14 and bodyweight in lbs x 17. The more bodyfat you have, the further towards the low end you'll be. Your low end would be around 2700 cal/day.
You would be absolutely fine to start there. Even if it is a little higher than you need it wouldn't hurt for a week two while you get stuck into Power Look. That way you'd be sure to be full of energy and recover really well which would build confidence.
Then, as you went along you'd gradually adjust calories downwards as needed - usually around 100 calories at a time.
It's worth noting that you would possibly see scale weight go up in the first few days simply because your carb intake would increase - which is fine. It just means your glycogen reserves would be full and you'd be holding more water. Generally the best thing to do is be guided by the mirror first and scale second. If you look leaner but the scale says you're heavier, there's nothing to worry about. A good idea is to use the same mirror with the same lighting and same distance.
Quite possibly. This is where you need to adjust as you go. Generally if you don't see progress after a week or two, you would want to drop calories. Day to day fluctuation is completely normal.
What the Power Look will do (with the right nutrition) is help you add muscle, so you'll look more muscular. Obviously you're more likely to add muscle while eating at maintenance than in a deficit.
Hell, I personally would say you'd probably do very well to eat in that maintenance window using Paul Carter's approach for the first cycle of Power Look anyway. I would be very surprised if you didn't like how you looked after that.
I disagree a bit. You'll look a bunch better with more muscle because you're not fat as such. You're just not very muscular. Plus, I have found it much easier to get leaner when I had a little more muscle.
Either way, if you're getting the right food in the right amount and training hard and well you've got a very, very good chance of seeing improvement. Like I said above, if you just eat at your low end maintenance (2700/day) with the macro split Paul Carter's article sets out while following Power Look chances are you'll be pretty pleased with your progress.
The real key apart from consistency and effort is patience. Even a year is nothing in your overall training lifetime. Ten weeks is a speck. I figure in terms of deficits, the smaller the deficit the better because recovery is what determines progress. If you can improve your look at maintenance, so much the better. That's where the mirror trumps the scale. If you can see muscle growing without extra fat accumulating, you're in a good position.
From where I sit, if you could run three cycles of Power Look at in that maintenance window and simply gain some muscle before even thinking of going into a deficit you'd be laughing because then when you did go into a deficit you'd have added an appreciable amount of muscle.