Well, April spelled it out for you, Caroline, JB would not take three hours to kill his family! No way!
Is this it? Is this the sum total of your theory?
You're relying on one of the more insignificant and obscure pieces of evidence to base your case upon.
You still haven't explained how Sheila battered Nevill. You stated that you don't know. In fact you've stated 'I don't know, none of us know, we weren't there' to anything that you can't even begin to explain.
Don't you see, you have your whimsical aga theory, whereas there's about 20 other aspects you dare not touch, because you can't come up with anything remotely rational.
For example, explain Sheila's appearance - no cuts, abrasions, bruises to hands or forearms, in fact none at all.
Her nails were in tact (this alone would probably be enough to dismiss a case against a live accused) having shot 25 times and reloaded multiple times. No gunshot residue on her hands / forearms which is an impossibility having fired 25 times. Clean nighty.
I know you say there was no 'almighty struggle', but there obviously was a struggle when Nevill incurred life-threatening injuries. Again, illogical to the point of absurd.
If you flip this on its head for a second, if you have the required cognition, if Sheila was alive, no court in the land would convict her given the described above. It wouldn't get to court, it wouldn't pass the simplest of tests. That's not reasonable doubt, it's absolutely no doubt.
You need to park your aga theory and just explain the above, then we can talk agas, pigskins and burns.