The removal of dewclaws, makes absolutely no difference, to how a dog might be able to hold a bone or toy. Dewclaws are just appendages, left over from pre-historic times, when dogs did not actually walk on the tippy toes, which they do now. Some dogs have front and rear dewclaws. Obviously rear ones, do not have anything to do with holding anything. Great Pyrenees and some GP crosses and a few other dogs, have the rear ones also. They are not usually even attached by bone and can easily be snipped and removed.
Incidentally, many other species, also have this left-over remnant of a historic extra toe.
I am all in favour of removing dewclaws. I can't even count, how many dogs I've seen (mostly hairy dogs) with dewclaws which have grown so long, they have curled and grown back into the leg. Ask any dog groomer, just how many they have seen. If I had a Great Pyrenees which I was not showing, I'd also have the rear ones snipped. They serve no useful purpose at all and can be a problem. Many dogs will actually nibble on dewclaws. I suspect, thinking that they are something which shouldn't be there.
Every litter I ever produced, had their dewclaws removed at two days. It is a very minor procedure.
Cropping and docking are usually up to the breeder, unless in a country where it is prohibited. However, in the US, where cropping and docking are usually done in a given breed, if you wish to show, then it's best to have it done. In Great Danes, we do see a lot more uncropped dogs being shown and winning. However, it was a difficult process and took many years, to have judges even give them a second look. When I brought all my GDs to the US with me, none were cropped. I was mostly laughed out of the ring.
Try showing an undocked dog where it is the norm these days, and you might as well save the money. There are a couple of Rotti owners, showing undocked animals, but they are few and far between.
One thing I must add though. If you do decide to have a dog cropped, make sure you are willing and have the knowledge and patience, to attend to and tape the crop, regularly and up to a year or more, if necessary. Nothing worse than seeing a cropped dog with ears which flop. It is not a quick or easy process.
Lizzie