A: No. Once you overwrite the exe, it is tModLoader only. To play vanilla, force the 1.4.4.9 beta branch in Steam properties, or use the backup you made in Part 3.
Steam automatically handles updates; if a new version is available, it will download and install it upon launching the client. Manual GitHub Installation download tmodloader 1449 updated
The 1.4.4.9 update isn't just a minor patch; it’s a refinement of the 1.4.4 core. Key highlights include: if a new version is available