If VAT and TAX are present you will have to capture both information, there are fields dedicated for this. Please find below the answers (in blue) to your respective questions:
There is column called level (8.01) and its mentioned that its derived by the system, what is this level means?
It means that information is aggregated from the different level - Line Item detail, Line Item, and header level.
Charge Rate, will this be given as % and is it expected that system should compute the charge amount based on this? If So on what basis this will compute the amount?
Please can you clarify what you mean by this question.
What is the difference between chargeable amount and additional amount?
Please can you clarify which fields you are referring to here?
Legal Text Place Holder – what is this column referring to and what information will be stored here?
Legal text is to be displayed on the invoice as required, this will depend on the legal needs of the country concerned.
Can there be more than one add on amount for the Line?