The Disney Photographer's are very easy to work with. Let them know what you want and it shouldn't be a problem. I'm sure they'll be fine if you choose not to do the funny poses they suggest.
Since you have PP+, you might want to have the 5 year old make a few funny poses or even the magic shots they offer. He might like to see them later. There is no extra cost which is nice. But I'm with you, the funny poses aren't my thing either.
I always ask them to take more than one picture. If my group picture has more than four people, I'd ask them to take at least three pic's. I might change the pose a little, maybe not. I want to be sure to have at least one pic with everyone's eyes open and a nice smile.
When I took my son, his bride & 2 new kids for their first visit, I wanted a family picture of all five of us in front of the castle. I told the Disney Photographer what I wanted. No problem, he snapped four or five pics with his camera. He even took a few with my personal camera. When we got home and I looked at all the pics both Disney and mine, the best one was with my little point-and-shoot camera. It's on our Disney Wall with all the others.
If you're taking a camera, ask them to use it to take your picture, they don't mind.
I'll mention.... There are a few things to keep in mind when you or the Disney Photographer take pictures.
If it's an over cast day most pictures will be Golden regardless of time of day.
Whenever possible have the people in the shot not in the direct sunshine, if you can get them in the shade.
Mid-day sun is the hardest for me to get quality pictures. But I still take them. I find the picture is a little washed out color wise.
Watching the time of day and sunshine when it comes to a Special Shot can make a difference.
I only worry about these points when I'm taking that one pic I know I want on the wall when I get home.
Don't let these things get in the way of having/using PP+.
Go and let the DP shoot away!!! You'll be happy to have all the pictures when you are home.
Enjoy your time in the parks.
Geemo
FYI
Here are a few opinion about PP+
http://www.disboards.com/showthread.php?t=3276530