Its my pleasure to provide you as much info as i can..Lets solve your paper of three compulsory questions regarding NAB..
1. Yeah.. Both are same. Hard workers call it hardship allowance and lazy ones call it NAB allowance..
2. This 100% allowance is given on running basic pay. It constantly raises with increase in basic pay.
3. No. Hardship allowance when approved was named as 100% increase in salary. Mean you have double basic pay only and field allowance of Rs.5000.