Hi Bhavana,
1. The FLASH should be good all the way through its temperature rating and it should work no matter what. The total number of write and erase cycles should hold through out the defined temperature range.
2. I do not understand question number two could you please reinstate it. Is it a question or an affirmation.
3. depending on where the Command is, if the power is interrupted it may very well latch the wrong data in. Pulling reset or a power down in the middle of a write sequence is never a good scenario.
Regards,
Nina