On a side note, suppose I lost my Electrum (seed) password, but I could retrive it eventually.
Now, I don't know if someone else could have had access to it, so it must be insecure to keep using that wallet with that seed.
Should I recreate a new one in Electrum and transfer all funds ASAP to this new one?
If you want to make sure your seed wasn't somehow compromised, then there is no problem in doing that.
Just make sure to never lose your seed. That's the one thing you need to know.