Hello!
I merged your threads together as they're similar, and I can answer them both together
There is nothing with changing GameSettings.ini so not to worry! We sometimes suggest editing that manually ourselves, if players are unable to change their graphics in-game for example.
Regarding lowering your graphics settings further - I'm unable to answer this I'm afraid. As technical support, we can only suggest using the graphics settings available to you in-game; I'm unaware of other techniques to lower your graphics further than that.
You could try asking our General Discussions section however, as this is not a technical issue query
All the best!