1.) Well, that kind of depends how much you're using it per day, no? Maybe 3-4 days with really heavy use? As long as it lasts a full day though...it really doesn't matter. Just chuck it in the charger when you're done.
2.) An hour? Plus or minus a bit.
3.) Erm, the warranty is three years. If your battery dies in 6 months, it'll just necessitate a phone call to logitech.
It certainly isn't the best mouse around for gaming, but its not bad. It helps to reprogram a few of the buttons for games though (keep scroll wheel in click-to-click, get rid of search button, thumb wheel). If you don't find all the controls you want in the logitech panel, try installing uberoptions.
1)Lasts about 3-5 days depending on use..Heavy use will grant you 2-3 days max.
2)About 1.5 hour at most
3)As it was posted if the battery dies before the warranty ends, you're covered.
Also As far as gaming goes, I absolutely love it, I had the MX1000 before that, and the main downfall was the weight, but now they shrunk the battery a bit and lightened the components so it's way lighter than it's predecessor.
Also, the side scroll wheel is nice when in Vista since it's used to Flip through opened programs, and the quick search thingie isn't that bad either (highlight a word, press the search button and you get a search result using your favorite search engine, pretty nifty IMO).
Battery life is good. I just found this mouse to be too big and heavy. The thumb switch could have been placed more forward...I find I have to continuously adjust my hand position to use it. Plus I find I can't use my fingers to move it around like a spider movement. Instead I have to move my entire arm around to use it properly...or at least more wrist movement. If you usually use your entire arm around (less precise) then it would work for you.
Mine is currently gathering dust. I went back to my trusty MX518. Which reminds me...I need to get it up on Ebay soon.