dude. why dont you search for answers yourself. Instead of writing such a long question you could have got an answer faster. Anyways to answer you questions.

1) Min sal 4000 Qr. no bank statement to show but you need an NOC letter with your salary mentioned.

2) No min stay as a resident required. You need to be a RP holder to apply for a family visit.

3) you need all certificates attested (marriage certificate, birth certificate etc).