1) Some airlines do as long as you have the type rating. You may want to contact the airlines individually. Some of the airlines in India are
a) Air India Express
b) Air India
c) Air Deccan
d) Go
e) Indigo
f) Jet Airways
g) Kingfisher
h) Paramount
i) Spice Jet
j) MDLR
2, 3 & 4) If you get a PIO or OCI card you will be required to pass the Indian exams. To apply for these exams you must have physics and maths at 10+2 level. I am not too sure if they will recognise your diploma as equivalent. That means you will have to redo your +2 with physics and maths. So the road to an airline job becomes even longer for you. There is no minimum marks required, however you must have physics and maths.
So my suggestion is to get in touch with all the airlines, ask they if they will hire you if you come with type rating and no experience on type and get it in writing. Once you have a company who will hire you, they you go and get yourself a type rating.
Second option for you is to come to India, pass 10+2 exams. Pass the Indian class I medical (current waiting time for initial class one is close to a year), pass all the Indian CPL exams, pass the Indian RT exam (or convert a UK RT to Indian RT), pass the Indian skill tests. Once you have done all this, apply with DGCA, once your license is issued start applying for jobs.
Didn't mean to scare you but thought I will give a true picture of what to expect if and when you come to india.
PS: Presently most of the regionals in USA are hiring low time first officers, have you thought of joining them?