Why is Sims4 legacy downloading on Win10 64bit, 64bit game version, 8 GB ram?

@WhoNeedsPublicID  There are a few reasons why the Legacy Edition might download on a computer that doesn't need it.  If you were playing the 32-bit version of Sims 4 before the LE was introduced, Origin will say you need the LE to keep playing.  Also, once you've added the Legacy Edition to your game library, it may automatically redownload even after you've uninstalled it, just like any other pack.  If this really bothers you, you can contact EA customer support and ask that the LE be removed from your account.

https://help.ea.com/en/contact-us/

But whether or not the LE is installed, you can instruct Origin to launch the standard version of Sims 4 instead.  Open your game library, right-click on the Sims 4 icon, select Game Properties > Advanced Launch Options, and choose 64-bit from the dropdown menu.

As for the language, have you ever installed TS4 in Swedish?  Are you in Sweden, or is your Origin install set to run in Swedish?  Other than that, I have no idea why the game would install in Swedish, unless you happened to pick the wrong language by accident when you were installing new content.