Moving to Germany from the UK in 2022

I will probably move to Germany soon (new job), I have a long list of questions but I will try to be very short .
You don’t need to answer every point, any input is greatly appreciated.

Here we are:

1. I am going to move without having fulfilled my pre-settled status, I understand that I will not lose my authorization to return to the UK if I return before 2 years of living outside the country, is this correct ? (I am from the EU and my pre-settlement was requested before Brexit)

2. What about bank accounts? I wish I had a proper bank account, maybe not like Revolut which is a half unsecured bank in the UK (£80,000). I saw DeutcheBank, N26 (which is probably a real bank), other than English support? The last thing I really need is to deal with German, I will study the language once there and it will take me a long time to reach the fluency required to handle such matters.

2.1 So the first requirement is English support
2.2 Better if he has a multi-currency account
2.3 Better if it has an investment platform, but to be honest I will try to find a good broker like IBKR or any licensed in Germany.

I would keep Revolut as a temporary bank account but due to registering with the UK address I only have a GB IBAN, it is not possible to have a DE IBAN as far as I know. I would eventually have to create a new account, which is probably not possible or it will trigger the deletion of the account I currently have…

3. Unfortunately I have quite a few investment platforms in the UK, will I have to withdraw the money from my ISA accounts and NO if I stay in Germany for more than 6 months?
Certainly I will try to keep my bank accounts and investment platforms open as much as I can, just in case I have to return to the UK… It will cost me dearly to move all the stocks and I have need to avoid it if possible… Admittedly, all the administrative procedures will be complicated if I am outside the country, especially if they ask me to verify my address, which I should change everywhere I suppose (including the bank accounts), at which point it would trigger the deletion of the account, I’m afraid…

4. What will happen to my credit score in the meantime? Suppose I am away for 2 years and cannot specify a UK address when I return, what will happen? Will it drop to a very small amount or just a little (for now it’s excellent)? I want to keep my options to return to the UK open, so it is important to preserve such a thing.

5. I also have different credit cards, should I close them too? How long can I keep them active?

6. Should I sell my car? The idea is to transfer a few critical things to Germany with my car (plus other things with a relocation service), then I would transfer them online if there is a service that does it from Germany, but always sold from the UK if possible.
Otherwise, I have to come back to Germany, drop the car off at a dealership, then walk back to Germany .

7. How does it work with credit cards in Germany? Is it like in the UK that I have to pick one up to start building my credit score, and slowly pick one up that really gives you money to spend? After years in the UK, I have positioned myself very well, starting from zero in Germany is again an ascent…

8. Transfers of shares are subject to a flat tax of 25%, is this correct? (after a small tax shelter of less than 1000 EUR).

9. Does opening multiple bank accounts reduce my credit rating? I think that initially I would open more, just to test them and see how I find myself between the website, the app etc, surely I don’t want to end up translating the page with Google Translate…

You don’t need to answer every point, any input is greatly appreciated.