The grab bag of fixes worked.
Try browsing to the '..\Documents\Larian Studios' folder and delete the 'Baldur's Gate 3' folder.
This folder contains the saved games, profiles and configuration files. Normally I would suggest renaming the folder for troubleshooting purposes, but if you don't have any saved games that isn't an issue.
Next, extract the replacement folder from the download below into your '..\Documents\Larian Studios' folder, and see if that will let you start the game. https://www.dropbox.com/s/jhv4qoopmmo1qeq/bg3_doc_41826359.zip?dl=1
The graphicSettings.lsx file is set to 1280x720 Windowed mode, Very Low quality preset and low audio quality, which you can change in the options (manually, or hit autodetect) if this gets the game working.