L1B expires on August and is it possible to opt for H1B this year


My husband is in L1 B visa from 25th June,2010.
He got his extention on January 2013 and
his workpermit was till 25th January 2015
(and visa upto 2018).
Recently he got his extention
of work permit and it extended upto
29th august,2015 and visa got extended to 2020.
His I-94 is till 08/29/2015…
I am in L2B and my I-94 & EAD both are valid till
My questions are:

  1. Is he eligibile to apply H1 this year?
  2. If his H1 got approved, in what basis
    he can stay here for the month of September
    as his i-94 is only valid till august 29,2015.
  3. If he go to his homecountry (India) after
    29th august, and decided to come back on
    1st october 2015, is it possible or
    his H1 will be null and void?
  4. Am I eligible to opt for H1 this year and
    if its got approved,how can I stay in US
    from 08/29/2015 to 10/01/2015 as I know L2
    is valid till L1 is valid…

Appreciate your help…
Thanks in advance…