I don't want to store all my wealth in a single wallet.dat file because if someone gained access to my laptop they could steal all of it.
But I am scared to split my wealth into several wallet.dat files because I've heard that replacing that file can make it unusable if you don't do it right.
I need a foolproof way of doing this. One where I can be certain that I am not going to lose the coins due to lack of technical knowledge.
I think it is an issue, indeed.
I wish there was a simple way to store some value and forget about it.
Correct me if I'm wrong, but I think you can be sure that a wallet.dat backup file will keep its value, as long as you don't use its private keys to send some money to someone else. Because if you do so, the software may have to combine some amounts stored in several private keys, and put the change in a new one.
So as I understand it, the only thing you have to do is to store your wallet.dat file somewhere, and remove it from your .bitcoin directory. The software will then start with a brand new set of private keys, forgetting about the previous ones.