Comment on Notice under Section 139(9)? - Possible reason
1. Since you have done intraday trading(considered as speculative business), you have to use ITR4. If you use ITR2 instead of ITR4, you might get a notice from the IT department asking to rectify and also might lead to a penalty.
2. No you cannot combine your wife’s, you will have to declare that separately. But if you intend to do this check out creating a HUF. http://tradingqna.com/2760/what-what-advantages-opening-trading-demat-account-which-huf
3. No, you cannot carry forward losses from ITR2 to ITR4.