Change in Company's Directors

Good Morning Everyone,

I am the director of a company X, company X has 2 directors including me. The company has also skilled worker sponsorship licence since Dec 2020.

The other director is resigning, and I will be the sole director of the company. Everything else including the company business, company name, address, size of the company, other details will stay the same.

1. Do I need to to report the change to home office?
2. Will that be considered as a takeover that would require me to apply for a new sponsorship licence again?
3. In order to protect my sponsored employee, anything else I should be aware of before my partner resign?

One more thing, just before I received the licence back in Dec 2020, a shareholder has ceased to be a shared holder on Oct 2020 (before we received the licence). At the time, I didn't report the change as I thought it doesn't need to be reported because it occurred before the issue of the licence.

4. Was I suppose to report the change of shareholder (not majority)?
5. If yes, If I report it now (which will be considered late), would that implicate our A-rating status?

Many thanks in advance.

Best,