We open sourced the launcher and hope to bring forth any C# devs that are willing to work on the Launcher and Improve it.
Anyone interested can send PR's and check out the existing open Issues on our Github. See below
https://github.com/TotemArts/Rx_Launcher
Ah speed limiting, you could use some program to limit it. I understand. However I will mention that if you keep up to date on updates, most will be maybe 1GB or a bit more.
Whats the issue? the launcher downloads updates compareable to torrents, as in it downloads blocks and can restart if its ever stopped. I'd love to see how we can help you.
You probably have an old install of the game, uninstall through windows, and then delete any leftover files/folders, then download the installer from the Downloads section and that will fix you up for anything in the future.