It's possible that someone who never used a Retina Display iPhone or iPad may be ok with it, but if you are used to a Retina Display in my opinion it's going to be somewhat challenging to get used to the iPad Mini.
Nope. Came from a 3rd Gen iPad and screen is not a problem.
Here's a crazy thought - play on one in the Apple store and make a decision, yourself. Don't leech on limited stock and prevent those who actually want an iPad Mini from being able to get one.
Seriously though, I'm so done with this screen argument. If you don't like the screen then buy an iPad, if you want portability and don't give a cr4p about PPI or anything like that, iPad Mini. Is there a need for all these threads? It's like a broken record!