Has anyone put a child seat in the passenger seat?
Is there a minimum age or weight for safety and legality? (I am in CA)
How do you turn the airbag off; and is it just the front airbag or side as well?
Is there a list of child seats that will properly fit in the passenger seat?

thanks in advance

Absolutely I do. Shown below. Essentially a fixture as my 5yr old daughter loves to rip.

Car seat is a CLEK. One of the highest rated seats. Fits very well. Airbag automatically turns off based on the weight.

It is forward facing - in Canada it is recommended your child is rear facing until at least 2...but recommended the longer the better. She lasted till 3 or so until she was too big.

She started in this car at 4.5yrs when I got it. Pics below.

thanks for the info .. is there a weight limit/minimum ?
my sons are 2.5 and 3.5 and would love to take them to cars n coffee

I think minimum weight by country/state as well as by the car seat manufacturer for forward and/or rear facing.

Once they are forward facing you should be good to go.

I waited until my daughter was 9 before she was allowed to sit in the front of a 2-seater.

I read somewhere that the child has to be a certain height and weight to be legally allowed to sit in the front. I think it was 4'8" and 80 lbs.

Certainly this isn't true in most countries; however, I cannot speak to certain states within the USA. Cars these days come with anchors for car seats - even coupes like ours.

Car seat anchors in the front passenger seat?

Just behind actually. I show it in my first photo...although I’m in Canada so I can’t speak to whether they are in cars in all countries.