F-1 visa Renewal

[saggymoon]

Scenario: My F-1 Visa expires in June 2019. However, the STEM is valid until June 2020. The STEM grants me a legal status in the US even though the F-1 visa expires. However, it might cause re-entry problems if traveled after June 2019. I have few questions related to F-1 Visa renewal during STEM. 

1) How well in advance can u apply for Visa renewal? 

2) Is having STEM-OPT valid reason to get F1 renewal?

3) Does applying for visa renewal make the current valid visa invalid?

Eg: Visa expires June 2019, but u apply for Visa renewal in Jan 2019 citing that u have one more STEM year. If the renewal application gets denied - does it mean the original valid visa( July 2019) becomes invalid too?
Wondering if this is a safe option - Since F1 visa is valid until June 2019 I can travel safely to India. If I apply for F1 renewal in Jan and even though the application gets denied since the original F1 is valid until June 2019 the re-entry shouldn't be a problem? Is it safe to assume in that way? And if the renewal gets accepted - will it cause any problems during H1?

Thanks for your time. 

[JGC94]

I have the same questions... F-1 Visa is going to expire soon while I will be on my OPT STEM for two more years