I am a fan of the FX series. I had a 7.5 and recently upgraded to a 7.6 It's a great bike for my 15 mile commute. I think it would be fine for a 20 mile commute as well (20 miles RT, maybe not 20 each way).

It will be fine for charity rides. It would not be ideal for a century ride though. If you decide you want to do a century on it, I'd look at adding Trekking bars to it (or maybe aerobars) to give yourself some extra hand positions.

The FX line are great bikes. In my opinion the 7.5 is the best deal in the line (I got a great deal on the 7.6, or else I would have stuck with the 7.5). You may want to look around to see if you can find a deal on last year's model. Also, I think they switched from triple to double chainrings upfront on the 2012's, but I could be wrong.