I rarely eat McDonalds, and I've never heard of doing this, but I don't see any problem with it.
I've heard of this but have never done it because my food is paid for by my work - whether it's at a nice sushi restaurant and starbucks, or subway.
I've heard of this. Same reason as above.
I've done this.
I've done this.
I wouldn't do this. I get my exercise in other ways and $1 isn't worth 5 blocks for me.
I've heard of this, but again, my meals are paid for by my work.
Cheap is like any other adjective, everybody has their own perspective on it.