I'm trying to convert hand-drawn line drawings into digital images by scanning them into my computer, then getting them into Inkscape using the "import" command. Once they're in Inkscape, I'm using "trace bitmap" to convert the images to a simple image, selecting the "centreline tracing (autotrace)" option to get a single line. 

Once I've done all that I use the "simplify" option to change the new image from a hot mess of nodes into a more simple image. 

The problem is that this seems to change the image, which means I have to go in and edit all of the nodes to make more sense of what I end up with, and that is taking a lot of time. 

I might have done this wrong as I've not posted here before, but I think I've attached two images: the first one is of a very rough sketch that I've scanned into my laptop, the second is of the image after I've done the whole trace bitmap and simplify thing on it. As you can see, the resulting lines don't echo the lines of the original sketch very accurately. 

Am I doing something wrong? Is there a better way to create digital versions of my simple line drawings, which will give me more accurate results?

I'm using a PC running Windows 10; a Canon flatbed scanner; and the touchscreen on my laptop to edit the drawings in InkScape.

For what reason you need to simplify? I got 654 nodes which might not optimal - but workable.

Because I do still have to edit the image to make it look good enough--I need to smooth curves, straighten lines, etc., and it takes even more time to edit it without simplifying.