My 505 is 2 years old, but I still go weeks between charges, and read multiple books in that time. I do notice that some books drain the battery faster than others. For instance, if the book has just one huge HTML file, instead of being broken up into smaller ones for chapters and the like, it drains the battery much faster (I guess because it has to calculate more for formatting of the pages, I know it has to stop more often to format the pages). On the last charge, I read all three of the Hunger Games books, and half of the Game of Thrones. I still probably could have eeked more out of the battery (it was on one of 4 bars of battery life), but figured that was good enough and put it on my charger as I went to sleep.
As far as holding up, I carry mine with my every day, pretty much everywhere I go in my netbook bag. I've dropped the bag once, and even dropped the reader itself a couple times, and other than a few dings, it is fine (The metal construction was a large part of why I went Sony). It has actually faired better than my netbook (which has developed some stress cracks).
On yours, a broken solder joint is actually pretty easy to repair for someone who is good with an iron, so fear not. It just is sad that they won't stand behind their product. I mean, a mechanical defect is not the same as abuse. Calling it a defect means that there was something inherently weak or wrong with it from the point of manufacturer.