what i was supposed to do if i couldn't reload the tx from raw text found on BTC.com? Waiting a possibly infinite time for having the tx confirmed, considering that it was propagated only by those few nodes accepting very low fees transactions?
if your translocation is out there, you will find it somewhere.
if it is not out there, and you can not find it then simply spend the funds again. in other words create a new transaction.
and it usually won't be forever. it is either dropped and forgotten, so to speak, or it will be confirmed.
Moreover without the chance to track it through Electrum itself... shouldn't the tx at least remain somewhere in Electrum cache and visibile in the UI (eventually flagged with some specific text warning about the pending/unaccepted state), in order to recover the raw text and/or directly re-broadcast the tx assigning a new fee?
it stays in your Electrum, not in cash but in your wallet file. you can open it in a text editor and see it if you like (although be careful not to change anything!). it is stored there but each time you connect to a new server, your wallet sends that server a request and asks it about transactions that belong to you and the server (the Electrum node) answers back and your wallet updates.
it is actually not a bad thing that not all servers have your transaction. imagine you didn't use RBF and paid a very low fee and now your transaction is stuck. when you have the tx in your wallet Electrum won't allow you to spend it. so you are screwed. but if it is not in your wallet (like when you connected to a new server and it disappeared) you can now create a new transaction with a high (appropriate) fee and resend it and hopefully get it confirmed fast this time.
However the above mentioned crashes using the command line were quite strange, right?
yeah, i have no clue why it crashes, sorry...
If i have to transfer BTC from two different wallets of mine, wouldn't be better to import directly the private key in the recipient wallet? Sounds faster, safer and cheaper in terms of fee
well i can't say if it is better or worse really.
for example if you don't want to move the funds and also if you already have that particular private key backed up, why would you even import it in a new wallet. let it be in your back up.
also it depends on your setup. for example where did this private key come from? is it another wallet? and what is the new wallet you are sending it to? for example if you have the private key from your Multibit and are trying to import it in a new wallet that you created with Electrum, you can not do that because your new wallet contains a set of keys (and new keys that will be created in the future) all of which can be recovered from a seed. but if you import this new one, this key can not be recovered with your seed so electrum does not even allow you to do it.