Sounds like you've got a decent plan to reduce the folder size. In deleting files ending with .ver1 .ver2 etc are safe to delete.
Technically, you only need the .save (main save) file.
If you're nervous to clean out the folder, copy the saves folder or even your whole Sims 4 folder to your desktop. Right-click the Sims 4 folder, select Copy and paste it to the desktop. This can be deleted once everything is cleaned up to your liking.
Then back in your saves folder -
-- \Documents\Electronic Arts\The Sims 4\saves
Delete all .ver1, .ver2 type of files. Keep the main .save files you have.
If you'd like to learn more about Sims 4 User Files, please see Crinrict's article linked below:
Sims 4 User files explained
https://sims4.crinrict.com/eng/2014/09/user-files-explained/