1) yes, either put them in the additional information section or on a separate sheet of paper (since you have to print the application and mail it to Sheffield)
2) yes, you are considered Settled because you are a British citizen and hold a UK passport. For the visa you either need to be living in the UK, or returning to live in the UK at the same time as your partner.
3) No, if you don’t have a job, you have to show you have 2.5 years worth of the £18,600 annual income in cash savings... but the first £16,000 or savings do not count, so you need:
£16,000 + (2.5 years x £18,600) = £62,500 in savings to meet the requirement.
This means you can only apply without the employment offer if you have £62,500 or more in savings, held in your bank account in full for at least 6 months
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