>when the vpn/tor connection drops
This provides a small metadata leak, keep this in mind.
>use a PC not a laptop
Why? Laptops are a nomads and dissidents only friend. It is mobile and easily disposable. You can make copies of encrypted drives incase of data loss, ensuring you are confident of your hardware before encryption.
Theft and surveillance is most effectively countered by encryption or anticipation of theft, not by how inaccessible your hard-drive is. If it is not feasible or recommended to rely mostly on encryption, it is still easier to relocate, conceal, or destroy a laptop and it components than a desktop. I however can't vouch for the security of hardware between the choices for which I am not a hardware engineer. I've read you can render a reliable thinkpad if you find an untampered BIOs and wipe the drive with a fresh OS. Write the boot sector to a USB or something if you can't trust your machine around others.
I would add that in the instances of physical theft, social engineering, or torture, there should be a method of preventing this. I wonder if this would work, hear me out:
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