Change from B1 to F1

[Roya22]

Hello, please help me to answer these questions..
I applied for stay extension on April 23rd 2019 because they gave me one month stay when I entered the States last time and I applied for extension because I need to stay more than one month.. now I want to apply an application to change from B1/B2 visa to F1.. and I need to know if I am allowed to apply more than one extension application even if they didn’t answer my previous one?? If yes, Can they deny my extension application while my change of visa is still pending? Or they will not decide about my extension application as long as change of status application is under processing?
Also my tourist visa will expire this con December.. can I legally stay in the states after my visa expired and in the same time my change of status application still pending?
Thank you in advance

[Magnitude]

COS L1 to F1 and then visa stamping from F2 to F1!!
Need immediate advise on below situation!!
I was on L1 and my spouse on L2 . I did COS to F1 which got approved and my spouse became F2 now.However, we didn't go for F1 stamping yet and my spouse now got admitted for Fall 2019 for her first Masters.
1) So, Now can she go directly to apply for F1 visa in India or she need to first stamped the F2 visa on her passport ?
2) Also, while filing DS-160 it's asking the last visa issue details so it should come as L2 which is in the passport or F2 for which COS was approved ?
Experts - Please advise!!
Thank you in advance!!