Matt Laur , Apr 29, 2012; 11:33 a.m.
Before you jump to any conclusions, Allan, partially discharge and recharge that battery a few times. Every lithium-ion battery I've used as improved dramatically after a few cycles. Regardless, buy a spare $40 battery for that $3,000 camera. If you're going to do a lot of live view shooting and chimping, especially in colder weather, you'll be glad to have one in your bag.
As for a hairline scratch on your mirror, are you sure you're not seeing an aspect of its actual design? I'm able to find but one report of a scratch, followed by a comment that one one talking to Nikon about it was told that it's part of the design, and o ignore it. Are you seeing it in the viewfinder?
And about sensor cleaning .... It's perfectly safe if you take anything like reasonable care while doing it. If a puff from a rocket blower and/or the built-in dust removal process don't take care of it, just clean it. You'll be using the thing for years, so you might as well get comfortable doing that basic chore which only takes a minute.
200 images in ... Keep shooting!