-> I would like to know why especifically this setup is not reliable, as I've seen some posts about it, cause for me is a great one... but i will appreciate your comments on the problems of it
I rarely see comments about unreliability of Electrum on Tails,
Perhaps it's those who are getting issues with wallet updates which can easily be circumvented by using the Electrum Appimage binary.
That was when it's essential to update because of the malicious server message exploit in the older versions; and the incompatibility with exported transactions after the implementation of PSBT. (
for those who are using cold-storage set-up)
Those mentioned are not an issue with the current bundled Electrum in the latest release.
-> There is also 1 especial point that I am confuse yet: Some people say they faced problems trying to recover the coins from a really old electrum wallet... why is that? what do I have to do for not having this problem in 10 years from now?
Those was the wallets before a critical bug in the wallet's key derivation function.
The fix made those very old seed incompatible with the later versions, it'll work but will derive a different set of keys.
But that was, as you said "
really old", in v0.31 (
Dec 6, 2011) and another upgrade in v0.34 almost on its early stage.
In the mature versions or even after 0.34, all seed phrases have been compatible with the latest versions.
I don't expect any incompatibility patches with the seed unless there's actually a critical bug with the current Electrum seed.