If there is no credible information (read indian involvement) means, there is no truth. I don think India as a nation would support any type of terrorist (even if it suits it or not) because we have a life example in front of us.
Yes we may not require 3 embassies/consulates for 3k indians.... But then we have lot of investment made in Afghanistan, and there is lot of work is going on there.... so these embassies are needed. Yes there could be another use of them, we have lot of stragetic assets at loose, may be a check on them is possible thru this agencies....
Note : I dono if this is an appropriate subject to discuss here....(im up for a discussion if needed, in any other thread)