Taxed on the *interest* not the orginal amount that has already been taxed. Always assuming your total income is above the personal allowance of course.
As a consumer yes, as a business only on the "value added".
Council Tax, though one could argue you are buying the council(s) and Police services. B-)
Do I? "value of the car" how?
Going in? Don't think I've ever paid tax when buying investments. You pay tax on any *gain* when selling if the total gains in a year are above the CGT threshold.
Gift allowance of £3k/year but I think that's £3k/year total gifts from one person. You can give more and it will be taxed but with taper relief over 7 years.
Some of the above is old knowledge, up to 5 years, but I don't think things have changed drastically.