How to combine a selected part of a component with another whole component?
You can only “combine” whole components together dear user. To do this you can either change the alignment settings a bit to let it fall together automatically on alignment or use control points all across the disconnected borders of each component and then realign to put them together.
and if I need to remove several points (select points using a lasso) from the point cloud after alignment (do not take them into account during reconstruction) … how to do it?
To tell the reconstruction what to use and process, the reconstruction region only can be used.