I highly doubt that it would be a big attack to begin with. Maybe a few people dead. That will do the job.
Tourism, security, attention on Kashmir didn't change after 26/11. Maybe a very temporary change at best. As far as government is concerned, the current government was re-elected by a landslide I believe, even after 26/11.
Again, it's what they consider gain/losses to be. Not us. Me and you will probably paint a simplistic gain/loss scenario. They're professionals so they'll work it through.
One thing is assured though, false flags are not some fiction or folklore. Look up Operation Northwoods if you don't believe me.
Not by landslide. At least not the center one. And people are not that happy with both the govts. Specially public of New Delhi are very unhappy already, by all the mess created by govt for CWG. What govt would risk adding up to woes of already discontent people holding up false flag in New Delhi. 26/11 took away post of home minister. If politicians had any interest in looking good in eyes of foreigners, Kalmadi would have resigned by now. They simply don't care.
You are talking about false flag in national capital, the city with max security, with additional security for CWG. Media would eat them alive!