$349 is a pretty good price - my local gun store has the LC9 for $379.
#1 isnt really about the LC9 is it? Isnt it more about the question of the 9mm ballistics? I believe the velocity generated from the LC9 vs the MP9 you mentioned is negligible.
#2 I believe concealed carry in any school or university is a federal offense - if you're talking about to/from I think you should be able to conceal the LC9 effectively.
#3 I'm pretty sure it's as accurate as the shooter. A recent gun-writer documented 2" groups at 25yds - much better than I can do at most ranges.
#4 The LC9 is rated for +P, but Ruger doesnt recommend a steady diet. Range time with regular loads, carry +P for self-defense.
The other point is that it is a spitting image of the Kel-Tec PF-9 which I have carried and shot for nearly 3 years. I would like to consider the LC9 because the sights are much better than the Kel-Tec PF-9 and it's got a very smooth "melt" for concealed carry.
However, there are a couple things that make the LC9 a less-than-best option for concealed carry:
1.) The LC9 has a thumb-flip safety similar to a 1911 - if you're used to the "thumb-high" grip on a 1911 then you might be ok with the safety on the LC9, otherwise your thumb could easily engage the slide-release, thus preventing lock-back on an empty magazine.
2.) The LC9 has an internal safety that prevents firing with the magazine out. This is a great measure, unless, in daily carry or in the heat of the moment you find yourself with a magazine that's not fully engaged.
I could probably build-in the muscle-memory to add an automatic thumb-flip to insure the safety is off when engaging a threat. However, the internal magazine safety I cannot recommend in a daily carry firearm.