I don’t know but if you have to ask the question then you know the answer: Once a corporation or government has your data, you no longer have any control over what happens to that data. It can be replicated, moved and sold many times over. So the only control that you have is the control not to let data leak out in the first place.
I know you directed the question to the OP but …
(I’ve had my phone for over 9 months so these are not first impressions but rather considered over many months.)
Good. Looks and feels well made. No awkward gaps. Nothing wobbles.
Solid enough. One of the smaller members of the household knocked my phone off a cupboard onto a hard floor and the phone survived the fall without anything cracking or ceasing to work.
The screen is clearly exposed. If you want that protection then you need a case. However see previous.
(I would have bought a case from Purism with the original purchase if it had been an available accessory.)
It’s thick but not infeasibly thick. Honestly, I am used to it.
It also depends on what you compare against. Compared against a thin iPhone that is not in a case, the Librem 5 is thick. Compared against a bulkier late model iPhone that is in a case, the difference is less significant.
The bevel at the back of the Librem 5 reduces the visual impact of the thickness, while not of course changing the actual thickness.