It is possible for the host machine to infect the virtual machine, its harder the other way round. Anyways, it is possible for the malware to record the screen and get your 12 word seed. Use one of your pendrives to run a live copy of Tails and you will be fine.
You can do whatever you want with the VM and the pendrive, just remember the 12 word seed. It is the most important thing in the Electrum cold storage. Pen drives can be prone to failure so I don't really recommend using them.
So just download Tails and do exactly the same thing just with cold wallet(no internet) on Tails and watch-only on a PC that's online.
Then store the wallet file on pen drives and remember + save the 12 word seed on a piece of paper in case of emergency.
That's gonna work and will be safe, right? Also, just wondering if the 12 word seed is the only thing that is required to get into a wallet, then isn't that not so safe?
There has to be at least 50-100 milion of people using etherum so it shouldn't be so hard to get into at least 1 wallet with random 10-20 combinations you write, no?