Ayeeeeemelia Please test the game in a clean user folder, to see which of these issues are still present. Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop. When you launch the game, a clean folder will spawn with no content. (Your saves and other content will be intact in the folder you've moved but temporarily unread by the game.) Don't add anything to the new folder yet; just start a new save and see how it runs.
If you get another crash, please provide a dxdiag. Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.
If you don't get a crash, but some of the other issues are still there, please let me know which ones.
The idea here is to see how much of this could be related to your saves or other content in your user folder rather than being overall issues. I'm not sure from your description, but some of the problems you listed could be bugs. The crashing is not though.