I think you do not get my point of view, I just want to know that in an IDEAL WORLD, the Electrum wallet on the computer with an internet connection is safe if there is no Malwares, no hacker's attempt etc
We use Cold Storage only to avoid any possible risk that comes through the Internet, Right? There is no other reason.
Look — in an ideal world, there are no malware and viruses. But in the real world, they're everywhere. The point of having cold storage is to erase the chances of you getting malware on your device. Because even if you're the most technologically savvy person in the entire world, you can still have malware with a slight misstep.
Look here, you said "potential vulnerabilities". if we are sure that there are no vulnerabilities in the system, then we can connect to the internet.
The thing is, how sure are you that you actually will get no malware/viruses? Just because your device's antivirus didn't detect any malware doesn't mean you can't have any.