I've broken several wire saws... if the strand itself doesn't break the eyelets come off... better off just chipping away at the wood you're trying to cut (may work better on bone... dunno).
There are LOTS of youtube vids and blog posts about altoids PSK packing/outfitting.
It depends on your environment a bit, too... items that have multiple uses are more valuable that single-use ones.
Consider the divine order and what you have on your person to achieve them:
1) Shelter - paracord on the knife sheath can help, a folded up 55gal drum liner can serve a lot of survival needs
2) Water - an unlubricated condom can carry about 1 gallon of water, toss a couple aquamira or iodine tabs or and you'll be OK for a bit
3) Fire - ferro rod and a couple tinder cubes (some like to pack petroleum jelly-soaked cotton balls in drinking straws with the ends melted shut, maybe a couple strike anywhere matches
4) Food - fish hooks and split shot, maybe a lure and some line (could use paracord gut, but line works best), some snare wire
Other items:
A button compass (better than nothing!), a razor blade, a hacksaw blade, some duct or gorilla tape is very useful as is a strong needle and some thread or thick dental floss, a few safety pins, a signal mirror is useful (some say you can use the inside of the tin to reflect light, but it's not very good compared to a dedicated signal mirror), put a whistle cord-end on your sheath, too - you can blow a whistle for help a LOT longer than you can yell, and the sound carries further.
Get creative, pack it TIGHT and water proof, and make sure to test & replenish/replace the contents from time-to-time as needed.
