This reminds me of my high performance and complex check ride in my Comanche. I had about 400 hrs in my Cherokee and just bought the Comanche. I think I flew it twice with the owner about 30 minutes each once before I bought it and once afterwards.
I ask the Local flight school owner, also CFI trainer at Flight Safety to train me and sign me off. A mutual friend a bonanza owner wanted to go sit in the back seat so he came along.
Nice day clear day but typical Kansas weather was a little windy about 20-27 knots. So we decide to go up. I went through most of the ppl check out maneuvers stalls in all of about 20-30 minutes and we hear ATC call out special notice to airmen for significant turbulence surface up and winds 37-44 and quickly worsening. We began to notice a bit of jostling above usual so we looked at each other and he said "That's good, lets go back."
So we head back and he asked do you want me to land? I said I am perfectly comfortable to land the plane in these conditions. It flies identically to the Cherokee with all traffic speeds 10 mph faster and the plane is 1000 lbs heavier. So I told him "I do not have insurance do you want to land?" he said "your plane." So I landed.
We made traffic pattern and turned a tight pattern but I was able to manage it pretty well and all in all it was a very sweet landing. Beginners luck but I knew how nervous my passengers were when they high five each other as I pulled off the runway.
I asked when he wanted to fly again and he said "your good to go, Tony." I think my sign off is .7 or .8 hrs.
Re PIC. It depends but if I am flying regularly and current then I establish what might happen in an emergency. Generally I fly, I go through the emergency check list by memory, you grab the checklist and double check me, unless I ask you to do some other task. Then we generally agree one person flies the plane and the other handles the radio calls watches for traffic.
Generally, if the co pilot has a commercial or CFI and has as many hours as I have or more then I presume his experiences are better than mine and ask him if how we prefers to handle emergencies. Its more about who flew the most hours in the last 6 months as my time is over 8-9 years and if his is over 2-3 years with plenty more landings than he is getting more frequency than am I.
When I fly with other pilots I do it pretty much the same way with the exception if they do not fly complex/hi performance aircraft I ask them to back me up.
As far as 3 people in the plane, I want the pilots in the front seat.