Hello Mayank,
Welcome back

.
1. Yes, you need to submit your 10th and 12th certificates to the CIO with your initial application. ALL of us have done that!
2. If any document is not in English or French, you will have to translate it using a professional translator and submit the translated version along with the originals.
3. Yes, ALL of the documents mentioned in the checklists are required with the initial application to CIO. Spouse's passport copy is one of them.
I suggest you go through the instructions guide for filing the application.
Thanks,
Indira Prabhakaran.