L2 visa stamping - passport expiry within 1 year, L1A petition approved for 3 years

[sandeep2020]

I have got an approved L1A petition for 3 years. Planning to schedule visa stamping interview in Jan 2020. Have a problem now. My wife's passport is valid till Dec 2020. I am planning to take joint appointment for visa interview and stamping. I have few questions:
1. Will my wife's passport be allowed to be stamped given her existing passport expiry is not valid for the entire period of 3 years?
2. If yes, will she get her visa stamping for the entire validity period of my L1A visa stamp validity period.
3. If not, will she get her visa stamping for only till her passport expiry period?
4. Should I renew my wife's passport and then go for visa stamping with her new passport? If yes, will it cause a problem as in my petition, I applied with my wife with the existing passport number as a dependent.

[Libra_14]

1. Will my wife's passport be allowed to be stamped given her existing passport expiry is not valid for the entire period of 3 years?

Yes, you need only 6 month validity at the time of visa interview & also at the time of entry into USA.

2. If yes, will she get her visa stamping for the entire validity period of my L1A visa stamp validity period.

Yes, visa will be valid for 3 or 5 years & she can later get a new passport & carry both (old & new) passport together every time, she travels in & out of USA.

3. If not, will she get her visa stamping for only till her passport expiry period?

No,

4. Should I renew my wife's passport and then go for visa stamping with her new passport? If yes, will it cause a problem as in my petition, I applied with my wife with the existing passport number as a dependent.

Depends on you & if you have time, if you do not want to carry multiple passports for next 10 years, get it renewed first.
If you are fine carrying multiple passports each time you travel, then no need to take any hassle right now - I carry 4 passports of my own, to keep records of all my international travels for last 25 years.