Thank you for your feedback!
I will add a few features you has suggested. Portable instalaltion works with copying the source code to any location. You just need the dependencies.
jdMinecraftLauncher is a Minecraft Launcher written in Python. It is a reimplementation of the old launcher, because I hate the new one. You can find screenshots in the Attachments. The Intercae is aviable in German and Englisch.
Get the source on GitLab
Unfortunately there is no binary aviable yet, so you have to install Python to use it.
1. Install Python
2. Open a cmd
pip install jdMinecraftLauncher
4. Now you can execute the Launcher by running
in the cmd
The functions that I use to install and start Minecraft are outsourced in a own library, so you can use it to write your own Launcher.