Yes, I get where you are coming from.
I like to know what I am installing too on my PC which is why I always opt, wherever possible, for a manual installation over an installation exe when installing or updating programs.Obviously though we can’t do this with Flight Simulator and we are somewhat at the mercy of Asobo. Even when we do manual installations though I suppose we don’t really have that much control and must have trust in the integrity of the developer
As for the sim buying planes etc you can always remove any credit card details/paypal authorisations for peace of mind 