As long as you've installed it safely in an airgap device, you have nothing to worry. This includes that you've downloaded the software from electrum.org and that you've verified its signature.

Generally, if you don't feel safe you should install electrum on a freshly-formatted PC in my opinion. As for the phishing links, that's a past. They disabled that JSON vulnerability. Still though, there's no proof that something similar will happen again in the future. It's a matter of common sense and knowledge after all.

If you consider that 1 BTC lots of money, just buy a hardware wallet and sleep easy.