Sorry to hear you are having issues.
1) Whitelist program : thanks for the suggestion, I have forwarded your suggestion to the Stardock support team for their review and recommendations.
2) Not to sure if you are using Start10 with your WB10. If you do, than your taskbar should be "Dark Mode" taskbar.
a) I've installed F.lux on my system but I don't see that "burn" blend you mentioned. Maybe uninstall and reinstall F.lux might do the trick. F.lux need re-calibrate your display setting when you install Windowblinds since it some theme changes your Windows System colors.
Alt+tab work just fine in my system. Preview windows still open up and I can choose which app I want to go. Maybe you can try the purge and reinstall steps : https://forums.stardock.com/486023/windowblinds-support-faq#reinstalling.
Make sure to re-download the latest version from your account. Install it. Reboot and retest. Report back here.
Stardock Community Assistant.