yes it is speculative but if it is effected through a recognised stock exchange than it will be out of scope of (even in nature it is speculative) speculative nature as permitted by explanantion to section 43(5).
2. if there is loss under above than it will not affected the requirement of tax audit as tax audit is based on turnover and not on profit and loss and in case of F&O both sides turnover will form pat of turnover as broker will earn commission from both sides.
yes as value denotes turnover and if it exceeds 40 lacs the tax audit is compulsory.