Would you recommend converting to Rupees to take advantage of interest rates. It is rather ambiguous from your query, whether you are returning for good or you intend to go back. Because our advice would depend on that. As far as Rupee is concerned, we see Rupee to depreciate further in medium term and long term. Indian interest rates may fall further.
Dollar still remains the safest bet.
Yes it will always be beneficial to keep your and your spouse's income separately. Besides this there are no other tax implications. I enclose some of the concepts which we don not understand but need to negotiate very soon with a foreign principal, etc. Your query is a little vague. What we gather is that you want to know the meaning of hedging.