Hi there,
You have a decent profile and GMAT Score. Please fin below the answers to your questions:
1. Should I re-evaluate my target schools given my GMAT score?

Yes, I would definitely suggest you to re-evaluate your target B-Schools, base on your overall profile and GMAT Score.
2. What are my chances of getting an admit to my target schools? I need to check your overall profile for this. If you can PM your resume, I can let you know your chances of getting admit to above mentioned B-Schools.
3. What are my chances of getting a scholarship? Again, need to check your profile for this.
4. Will my lower than average GPA and lower than average extra-curriculars be a problem? You can offset them through other parameters like your GMAT Score and work achievements (if you have any)
5. Will my pathetic IR score be a problem? same as above
6. Could you please suggest some b-schools, better than my target schools, where I'm likely to get an admit? Can suggest, after having a look t your resume.
You may also gauge your chances of getting admission in a top business school by trying this Chances for B-School tool
https://bit.ly/1rRCod5Hope this helps.
Cheers!