> Using the least amount of security features is a huge amateur mistake.

Not understand your threat I'd say would be a even bigger amateur mistake, you're not trying to protect yourself against some forever 3rd party attacker here, you're trying to prevent a agent rewriting the wrong file on your disk, that's basically it.

Give it the least amount of permissions, don't bi-directionally sync stuff, pass things in, then take them out again, literally the agent couldn't and wouldn't try to break through 2 layers of security in order to get your banking details or whatever.