I'm a bit confused when you say they are rhizones.* Maybe that's a typo and you mean rhizome?* Even so, I've never heard of the roots of blueberries as a rhizome.* Maybe they are just a mass of roots?*** If they are nearby your blueberries they are probably already crossing with yours if they bloom at the same time.* Any that have entangled roots won't survive the transplant with what you describe, and digging them up will only destroy them.* Besides, unless you own the woods and the plants in it, digging them up is not a good idea.* If it's public land, that is against the law and is considered morally wrong by most folks.* Most plants dug from the wild don't survive the transplant anyway.
You don't say what varieties you have, but having more then one in your garden is best for a better harvest.* For larger berries you would need a varitey that has been selected for larger berries.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.