NON-EU with RC and Divorce

Hello everyone,
I have a several questions;
As an non-eu citizen and married for more than 4 years and living in UK more than 3 years. Less than a 2 years will apply for ILR. my EU partner is working and I do. We also planing to apply for pre-settled cause of Brexit.
if;
1-non-eu citizen open a case for divorce that does effect to apply ''retained right of residence'' ? or eu citizen open the case ? Does it matter who opens the divorce case ?
2- Does ''retained right of residence'' is giving by court( I have saw some people get from court) or after the seperation person does apply ?
3- As a living in UK from 2016 and married for 4 years do I (in case of divorce) getting retained right of residence ? How certain I can get pre-settled or ILR ? (After divorce)
4- Divorcing after ILR can cause anything for citizenship application ? or effect on anything else ?

Anybody has any idea ?