The answer to your 1st and 2nd I don't have, as neither live in india nor know someone there.
The 3rd goe like this: all of PS3 titles (or almost) install on internal hdd but you still need the BlueRay disk-- no DVD based ps3 games -- for the disk based games. there are games you can download via PlayStaion Network (PSN), whch also are available on disk and getting one version doesn'y give you the other.
As for the 4th, all the information is availabale on playstation.com. but let me put ot this way, unless you lay your hand on some old models (20,60 -- hardware emulation through EE, 80 Go lack EE but still software emulation -- heard GS still there) you wont be able to play you're ps2 games. as the newer models (an 80 and a 160 Go --no more GS) lack the hw parts that enable ps2 emulation.