Thanks for your questions - I am Sam and I am one of the UK tax experts here on Just Answer.
1) You must have registered with HMRc within 3 months of this consulting work having commenced
2) Rental income is not treated as trade income, so this is ok just to add in as income without the need to register within a 3 month period
3) For business costs a ratio that represents a true cost for each source of income - but only home costs if you have a room set aside for the consulting work which should be heating and lighting bills x hours actually worked/total hours in period - if no actual room for business then £3 a week but NO council tax allowed -
For broadband again a ratio that represents business/total use
Mobile bills if contract then ratio of business/total use if no contract and PAYG - then if not just business than NIL
4) Car you have a choice of mileage method which is 45p a mile for the first 10,000 miles and then 25p a mile thereafter OR the actual method which requires you to keep a note of total miles and business miles to establish the business percentage which you can then apply against the costs to run the car and also the car can then be treated as an allowable claim for capital allowances.
5) Advertising - public or professional liability, laptop, printer and stationary might be furtehr allowable expenses - maybe stamps
6) I have no idea what this means - the costs should always be justifibale in proportion to the source of income against which they arise
7) None of these costs are allowable as we all have to eat and drink to live and this is entertainment costs and not a business expense
If you have any follow up questions, then I will respond tomorow if that is acceptable, as I am off to bed as its been a long day