@Kittekassitar For now, try bypassing the launcher entirely. Since you're on patch 1.67, you can launching the game directly from TS3W.exe without opening the launcher at all. That should at least eliminate the launcher as a source of issues. If you don't have a desktop shortcut for TS3W.exe, you can find it within the game's program files, probably here:
Program Files (x86)\Electronic Arts\The Sims 3\Game\Bin
Please also let me know what in-game framerates you're seeing. If you haven't taken steps to manually limit it, your fps could be far too high and cause all sorts of issues. To see your framerates, bring up the cheats console (crtl-shift-C) and enter "fps on" without quotes. Let me know both the steady number and whether you get significant fluctuations. A rough estimate is fine for both.
If you still see lag, please open the Task Manager and end any background processes with the name Nahimic or AVolute, then test again. (Any essential processes will restart the next time you reboot your computer, so there isn't any risk.) Your dxdiag lists a couple of Nahimic crashes, which may or may not be game-related, so it's worth testing.