My sense is that women in their 30s are at a disadvantage at OCI. My sample was quite small, so take that with lots of salt.
I have heard this. I've heard people recommend that you 'forget' to wear your ring (if there's a ring) on the day of your interviews. Sad but true.
I am about to start law school part-time in August, but I have worked at a 400+ attorney law firm for the past 5 years. While gender, age, and attractiveness affect any job application process (and differently at law firms), it's hard to guarantee a general trend, or one that is very different from other lines of work. A hot 25 year old blonde woman is going to have an easier time in life in general that a chubby 33 year old guy. Such is life.
Yes, it does seem that attractive women are hired to be associates due to their looks* and the fact that it is fairly certain the young lady will be married off, breeding, and easier to push out of the partner track in 5-7 years. But that doesn't mean that that is the only factor or even always a positive factor in employment decisions. Talk to the female attorneys in their 40s and 50s...they often have a very different view on hiring young, perky, definitely-going-to-be-moms-first female associates. Many of these older ladies feel they had to fight harder than their male counterparts to get where they are now, and seeing young women today not realize whose shoulders they are standing on causes friction. Besides this, most businesses, including law firms, honestly do want to make money, and while some will get hired based on their looks/availability, for the most part you will get hired on who you know or what you can do MUCH before your looks.
With the wedding band thing...I think that is appropriate for about any job interview. They cannot ask you whether you are married or not, and wearing a ring is a near certain answer to that question. I have taken my ring off (I'm a dude) for interviews when I thought it would matter at all. It's none of their business at that point.
*What's the best thing about 24 year old female associates? The fact that they're always 24. Sorry, couldn't resist.