Have you tried LibreOffice Draw? It's a much smaller and simpler program than Inkscape, with more limited features, but it has all the basic drawing tools and primitives.
It supports SVG import and export. You can use a Wacom tablet with it, but I don't think it will detect things like pen pressure and tilt.
There is also svgcleaner.
As of the time that I am posting this, the latest release was in April of 2018, and the latest (unreleased) commit in November of 2019, so it can still be considered in active development.
I do not know how it compares feature-wise to the other utilities listed, but the main benefit I see in this utility is that it is written in a ...
Currently I am working on a C#/.NET project where you you can give the name of an organic compound and the image of the compound will be generated.
The code of the console and WPF app can be found here https://github.com/thieupepijn/OrganicCompoundVisualizerWinApps
The library behind these apps can be found here https://github.com/thieupepijn/...