I would like it to be possible to enable or disable some things, or even modify them.
Like: version selection (or perhaps already recognizing the version used), and more.

Could you elaborate on what you mean? Like what specifically would you like to enable/disable? And how would modifying work?
Additionally for the version selection it should already infer the current Minecraft version and set it as the default if it can find it in the service's version list.

I didn't understand your sentence about the list of versions. But I think it would be interesting to be able to disable or enable small details of the modpack, as it would help to better adapt the modpacks and make them more customizable

Over the last few versions a lot of config options have been added, as well as theming in 1.7.0, if you want any other config options, please create a new issue with the exact option you want.