I read with interest your queries and the answers provided by other experts. I just want to add few points:
1) The income earned by your friend, who is a resident in India, is earned outside India but is still taxable in India. He will be entitled to claim double taxation relief, if any taxes are paid in the country in which such income arose.
2) As your friend is a passive investor, the nature of his income is not business income but can be capital gains or income from other sources.
3) The management fees paid deducted by the service provider is expenditure incurred wholly for the purpose of realising earning income. If its a capital gain, then the sale consideration can be reduced by the expenses incurred on such sale. If its income from other sources or even business, still the management fees can be claimed as an expenditure.
4) If the income is more than Rs 50 Lakhs, the details of all moveable and immoveable assets shall be given in Schedule FA.
5) The income may be received in his individual capacity but he should be able to establish sources for the investments.
As regards other legal requirements, the other experts have given clarifications on which I have no other views.