A drilled hole might cut through even the toughest line if it gets twisted/caught and you could lose your hook - or worse, your catch. I'd make sure you file that hole down to make the edges rounded over.

Could be a decent lure too, I hadn't thought of that!

You can shape and fold a piece of tin foil into pouches, cones, pans... lots of useful shapes. I've been looking for the best aluminum for the job, but haven't found it yet. Done properly, they don't even leak. Those Gerber milk bags seem pretty useful and small if you want a backup water carrier to your bag. The suggestion to use a disposable aluminum pan is interesting... also affords some protection to your kit since it's just in a bag.

Your kit is nice and gives me some food for thought!