Re: Red Flags
I guess the biggest red flag would be if they were pushing for a commitment, almost to the point of badgering you to agree to the Rishta..
Another would be the making of demands. If either family set certain "demands" relating to the engagement. wedding, living arrangements etc etc.
My aunt was looking for a rishta for her younger brother, (my uncle) and they went to visit one family. The girl, mum, dad and 3 brothers were sat discussing the rishta. The father said something and one of the brothers just looked at him and said "Dad, be quiet. She is our sister and we know best". The brother started making demands such as demanding that every Eid, Shabraat, birthdays, weddings etc etc, she should be sent back home here and when you send her, she should have nice and new clothes, but not just any new clothes, they should be of the latest fashion. Another brother was saying that at the time of the wedding she should be gifted, jewellry, watches and money, preferably money. All the time the mother and the girl just sat silently and were never allowed to speak. I feel sorry for the wives of said brothers!!
If both backgrounds are very different, this is a big flag. You need to have commom ground and if you're oil and she's water, you're never going to mix!
Level of religiousness is another. If you're a girl and marry a religious boy and you don't cover/wear hijab, it's obviously going to cause issues. if you mix with men, have male friends, said religious man is not going to agree to this.
Differing outlooks in life. If he sees children and grandkids and all she sees is her career, it's hardly a match..
You can usually tell by the way the MIL/FIL talk, if they are forward thinking folk.
Look at the siblings and how they present themselves. Do the sons/daughters walk in and out the room without so much as a Salaam, Aap kese ho?.. How are the sisters dressed, jeans and top, or shalwaar kameez? (Ok, if she's come in from work/college/uni but not so much if its 1pm on a sunday afternoon.)
If they are preparing a meal for you, (because you have come from along way), is the mother in the kitchen, or sitting with you and letting her daughters/DIL's handle it. If she's in the kitchen, shes probably bossing them around to hurry, get the best china out, etc etc. If she is sat with you, then she trusts her DIL/dauighters to handle everything as they have been raised well and now how to treat guests..