Tax case: Resident alien who permanently relocated back to Europe

Hello.
I hope you are doing well.

I had lived and worked in US around 2.5 years with L1B working visa (resident alien status) and permanently relocated back to Europe this summer (beginning of August).
I know that I will still retain a tax residency status in US for some time and will have to pay taxes both in US and Europe.

Q1: I was not able to obtain a Sailing (Departure) Permit from IRS due to a long appointment wait time. I called them in the first part of July for the appointment and it was scheduled in the middle of September despite I had told about my plans to leave in 2-3 weeks.
Is it possible to obtain the Sailing Permit abroad?
How critical it is?

Q2: I'm planning to file taxes to IRS for 2024 and no more AS I'm not in US since the beginning of August 2024 AND I won't meet the substantial presence test for the 2025 year. Does it sounds correct?

Q3: I still have some money and stocks at US banks.
Will it be possible to sell those stocks at 2025+ being a tax resident of another country?
Do I have to sell OR transfer those stocks to Europe somehow this year?
Should I avoid any taxable income (interest, dividends, etc.) at 2025 for the money/stocks present at my US accounts if I won't transfer it to Europe?

Q4: How soon should I fill and submit a W-8 form since I left?
I need to submit it to every bank entity at which I have accounts, right?

Q5: Are there any possible issues with US credit cards usage once you become a non-resident?

Q6: Are there any other important tax points should I consider in my case?

THANKS!