Remember the bit about the camera needing to be in Manual mode to balance (or for the flash to overpower) the ambient.
.... Try a toy about head size and a reasonable shooting distance (5 feet) - ...
For the toy; Try ISO 200, 1/100 and 5.6 and leave the flash on ETTL. That'll give you a flash lit shot. Make sure your ETTL metering is set as centre-weighted, it's a custom function - ETTL wants to use a metering based around the focus point and it's rarely useful in real life.
With those settings and distance, you should see the difference you can make by bouncing the flash (ceiling / wall / reflector) and using some FEC. Then you can incrementally open the aperture and up the ISO and see where the ambient creeps in with it's own exposure.
Hope that helps.
...
Damien
By trying so many variables, you're not really helping yourself

. Start simple, one camera mode one flash mode - get it working, understand what it does, then try something else.
I think I know what I'm doing - I have been using manual and auto flash for twenty odd years, ettl for ten, and I haven't the patience to pick through your results above to sort out what you or your camera or your flash might have got wrong (it could be any one or all 3).
You need to be in control and all you're doing is choosing random ways of trying to make the camera do it for you - you'll never get consistent results that way, so even if you do get one good shot, your chances of understanding and repeating it are minimal.
From earlier in this thread - remember that the ambient and flash are treated as
two different exposures. If you want to see what your flash is doing - make sure the ambient isn't muscling in. When you've seen what your flash does, bounce it - modify it, get it right. When you've got it nailed - add the ambient as fill for the background. When you've got it nailed, try the ambient as main light - and add the flash as fill. All that should take you a week or longer.
Trying to do it in ten minutes is like sitting at a piano for the first time and thinking you can knock at some Rachmaninov

.
Most of us have spent longer adjusting the lighting for one portrait than you did for this entire test:shrug:, you'll never learn from shooting 1000 random shots and asking someone else what's happened. Read the advice - set up the shot and experiment - with settings and angles and bouncing - not with a million different modes.