Application questions

[ibmfreak]

Hi all, Thankyou for reading my post. I am planning to apply for my British citizenship application in August and had the following questions.
I have lost my previous Indian passport so I don't have the exact dates when I arrived in the country. I know the approx dates but dont have the exact once and my old passport.
However I have got a letter from the HM revenue which confirms the tax and jobs I have done in the UK. Would that be sufficient.

I lost my degree certificate which I got from a UK university. Its easy to get it but the home office has a record of that from my previous applications. Do I need to submit one with my application.

I lost my life in the UK test certificate, I have gone through the forum and it confirms that I can contact the home office and they can give me the test number. Do i still need a copy of the Life in the UK test certificate.