Posted by dellus on Aug 06, 2017; 10:01am
URL: https://forum.librecad.org/How-to-Create-a-Block-tp5715012p5715157.html

The problem with erratically jumping of to be moved or rotated entities may be due to 'free snap' not activated, so the snapping point will jump to the next possible position. With 'free snap' calm movement becomes possible. You may also switch off snaps you don't want to use, like 'grid'.
You can easily set an exact rotation point at the command line when it says 'specify rotation center' by entering the coordinates (x,y) or relative coordinates (@x,y). Alternatively you may also draw an auxiliary line having start or endpoint as the rotation center and use the mouse to snap to that.
There are some manuals at the wiki, though partly outdated they can help about the general working of LibreCAD.
Concerning blocks (and also hatchings) there are many known deficiencies. But you have to take LibreCAD as it is, as there are hardly any developers working on it and no one to aim criticism at.