L2 EAD to H4 due to status change of principal from L1 to H1

[Prash]

Current Status :

I am currently working in USA on L1 Visa which is under extension application process and with Valid I94.

My spouse is on L2 Visa and got her EAD which is valid for next 2 years and started with job applications.

Potential Change :

Meanwhile my client offered me a job considering my earlier H1B vISA.

Background :

I was holding H1B Visa 5 years back (Valid from 1st Oct 2007 to 13th Aug 2013 ) and was not utilized.

When I changed my job in India my employer cancelled stamping on my passport in India.

Later I came to USA with L1 Visa in 2010 for 3 months and again in 2012 and currently in USA for last 8 months.

Total stay in US : 1year 2months.

Questions :

1. My client is saying they can use my earlier H1 and will just Transfer it and need not have to apply for new H1. Is it really possible ?
   
2. In case it really happens then my status will change to H1B. In that case do I have to apply H4 visa for my spouse immediately ? Is it ok to continue with current L2 EAD
   

Please reply as it turn out to be complicated situation for me.

Thanks

Prash