N400 - estimated case completion time vs wait time

[Cyberbully420]

N400 application filed 10/09/2018
Biometrics completed 10/30/2018
No updates since then except for three "transferred you application to another field office for review" events
Estimated case completion time shows November 2019 (top of the page)
Estimated wait time shows 14 days (bottom of the page)
Questions:
1. What is the difference between the two estimated dates and why is there a discrepancy between them?
2. How long before the scheduled interview date does the USCIS generally send the appointment notice (online or in the mail)? i.e. how much notice do they give?
Off topic question:
3. Can one travel on a US passport to India, if the renunciation of Indian citizenship is still pending and/or has been applied for but is not complete?

Thank you.