When you extend your seed phrase with a passphrase, you get a new wallet that can only be opened with your seed phrase + passphrase, and just the seed phrase will open only the base wallet. If you have funds in the base wallet, you can make the criminals believe that is all the BTC you have, so they take it and go away, that is what is plausible deniability. It is certainly risky, but it is something that could work.
This is good idea, except for the situations where criminals know how much you have.
You've been talking about guns so much in this topic, what's your point. You can get a gun to protect yourself if you want, that is fine, but i thought the discussion was about non-violent ways of protecting yourself, i.e using solutions relating to the BTC network.
It's about all solutions, violent and non-violent - whatever it takes.
As for guns, well - it is the best tool against physical attack that man has invented so maybe that's why as this topic is about physical attack.