I wish I had bookmarked the article I saw some months back that cited some statistics showing that UPS and the USPS lose packages more often than the airlines! Not, of course, that airlines don't lose things. I've never had a package lost by either, though, and luckily I've never had the airlines lose anything of mine, either. Do some redundant labeling both outside and inside of pack and tape them down securely. Include your destination in case the airline tag disappears. Note that delay of the luggage occurs far more often than actual loss.
If you can squeeze your pack into an overhead bin, you can carry it on--just make sure your little bottles of liquid are kept out in a quart freezer bag for the TSA check. However, you will have to check your trekking poles, knife and/or scissors and buy your fuel at your destination. Butane lighters, on the other hand, have to be carried on. I still haven't figured out the sense behind most of these TSA rules, but of course they didn't ask me!