L-1 Visa

I have a question about my mother's stay in the US on a visitor (B2) visa. I am an IT Professional in the US on an L1 work visa along with my family (spouse & kid). My only sibling (younger sister) is also settled here in the USA. My father passed away a couple of years back in India. My mother is 60+ years of age, and currently, there is no family member in India to stay with her at all times. She visits the USA and stays with us for six months at a stretch during the year. Considering her health and emotional support needs, I am looking for options to have her stay with us long-term (beyond a six-month period in a year). As is the case in this scenario, are there legally valid options/exceptions for old-age single parents?

1. I am on L1A, and I have Approved EAD and AP. Also, 180 days of waiting is over.

My question is, can I switch employers? If so, how will USCIS match my job duties? 

2. On L1A, it's an International Manager experience, and how can I show that I have international manager experience with the new Employer?

During the last three years on H-1B, I have spent approximately one year outside of the US (multiple visits to India). What is the procedure to recapture that time and add it back to my H-1B total time?