OP, I suggest you don't get an iMac, you seem to be worrying about all the trivial things, making it really seem like you don't need one. On that aspect I would say yes get a mini.
Who cares what everyone else says? Buy the mac, and by god do not go looking for these "defects." You will become paranoid and think there is something there but in reality nothing is wrong with your display. I purchased a new 27", I love it. There is nothing wrong with my machine. Stop trying to get advice from a help forum where the people who have all these problems// frequently look.
Check out your iMacs at your local Best Buy or Apple Store. Ask your friends, your neighbors. A help forum is not the place.