how to replace objects in an easy way

In my village a lot of buildings are not signed on the right spot. How can I just click and replace? Till now I had to replace all points of the object.

This depends on the editor. Your edits seem to have been done using iD, so, select the house, right click, and choose the second icon from the menu (a dot with arrows pointing up, down, left and right). You can drag the house.

Unfortunately there is another problem with the house I tried this on; it is blocking one side of the road, so you first need to disconnect the problem wall from the centre of the road. To do this, select the house, then select each corner in turn and right click. Again it is the second icon (the dot with arrows pointing left and right, this time), that you need to use. You can then move the house.

As well as moving, you can use the next to last icon on the area menu to rotate it.

With more sophisticated editors, you can disable the road, so that objects drawn close to it do not snap to it.

Maybe there is simple an imagery offset?
Also keep in mind to sign the position on the ground and not the position of the roofs.

Also as a helpful hint, if you select a building in iD and press ā€˜Sā€™ you can make the building rectangular. Same function is available in the context menu if you do a right click.