Does my current L2 EAD valid with new L1B/L2 petition?

[MMAN]

Hello Experts, Need your valuable inputs in my situation.

Currently I'm in L2 visa with EAD valid till Jan 2019, me and my spouse had to go for new L1B/L2 stamping from outside US even though we have I-94 valid till Jan 2019, but my spouse L1B employer wants to file either new petition or extension based on I29S which is expiring on September 2017.

Q1- Can we stay and work in US till valid I94 and with expired I29S ?

Q2- If we go for stamping from outside US and approved with new L1/L2, does my current EAD valid till it's expire Date Jan 2019? Or Do I need to apply for new EAD with new Petition?

Q3- If I have to go for new EAD, should I need to resign my current job as the current EAD is invalid or I can work with old EAD in the meantime or I can go on 3 months LOP leave.

Q4- If we go for L1B/L2 extension in US and approved, I'm thinking that EAD extension is required only 120 days before Jan 2019 assuming L1B/L2 petition remains same. Please correct my understanding.

 

Appreciate your response! 

Thanks