If it's a residential property then you benefit from a rebasing so you only pay CGT on the gain in value since April 2015 (if you held it then).

You can elect to base this on the 2015 market value, straight line basis or acquisition cost.

Can you explain when you moved into the second property and when you ceased living together. it isn't clear from your original posting if they were the same time or not.

The entire table is a massive (albeit common sense) extrapolation from a few sentences in the legislation so there is no right answer to this.

I would go with rental income net of expenses but before tax. That is fair, justifiable and accords with the general intent of the legislation.

if the land is used for a business, maybe. If not, no.

As a sole trader, you are your business and your business is you. There is no distinction. There cannot be tax on you introducing or removing funds from the business.

1984. it's just that legislation.gov.uk always shows 1991 as the earliest possible date.

As you know, you will have the original acquisition value of the whole property. In the absence of an election, your main residence is just your de facto main residence. A married couple can only have one PPR while they are living together but you can have different PPRs once you are living apart. S...

Only if you are filing a return anyway, otherwise no.

Yes, you can do either. If he is the beneficial owner, he will be liable for the CGT on a sale but no CGT would be payable on a transfer to him (because he is already the beneficiary owner). Incidentally, you would have been personally liable for income tax on dividends while he was under 18 but not...

It's unlikely but one that you should definitely get professional (paid!) advice on as it is so fact specific.

Also bear in mind that if others have done it, that doesn't necessarily mean that HMRC approved it, they may have just not been aware of it or failed to review the tax return properly...