Blanket L1 amendment

[amju]

Hello All, 
Need help with Blanket L-1 visa amendment process. I have Blanket L-1 visa approved and valid till Nov-2018. I came to US in Dec-2015 to work for client at location A. The project is going to complete and planning to move to a different project in my own organization at different location.
So they filed amendment of my visa to USCIS for change of work location. While submitting the amendment, they also requested for extension of stay beyond my visa validity i.e., Nov-2018. Now USCIS issued RFE :-((.

My questions are below.

1. To change the project at different location, is it required to submit the amendment for Blanket L-1 Visa?

2. Is it mandatory to respond to RFE? If not responding to RFE, what will be the outcome from USCIS?

3. By not responding to RFE if nothing is going to happen, can I submit another amendment to change work location?
OR
 Is there a way to withdraw the RFE and submit a new amendment just to change the work location?

4. After submitting the response to RFE, if in case USCIS denies the amendment, as I have valid visa till Nov-2018, can I submit amendment again to change the work location?

Thank you in advance