While Tums has some antimicrobial properties, it is NOT considered an antibiotic. So, it's good for heartburn, and might help a little for diarrhea, but I'd just as soon take it out and leave it up to each traveler to get their own prescriptions. Don't think Tums will cure an E coli or cholera infection.

Re alcohol and antiseptic towlettes. I'd take out both. While they have their place, I don't know that they aren't more useful than soap and water for the things you'll be doing. "The solution to pollution is dilution," so don't be afraid to copiously irrigate wounds, assuming blood loss is controlled. Add in more benadryl or tums or something. Tylenol, motrin, butterfly bandages, something.

TQ's are easy to improvise, as Hikermor said, if you know what you're doing. If not, the CAT-T and SOF-T are the current recommended ones by the US military, but they're pricey. I don't have experienc with other brands.

Do those medication compartments come out? Or are they permanently molded? Can you cut the dividers with a pair of scissors? I know that some meds can come in very small bottles, but you're right in that it's probably easier just to stick with individual packets if you're stuck with a pre-mold box. That's why I prefer a bag

Compressing gauze can save a LOT of room, particularly if you have Kerlix brand gauze rolls. Think of going from roughly 2 inch diameter to 1 inch diameter, and a little loss of height. It can probably double your supply, possibly triple if you really pack it tight. Same for the gauze pads.

BTW, I don't know if you mentioned, are the gauze pads individually wrapped? If so, I recommend swapping out for bulk pads. Relatively clean (shrink wrap or throw in a sandwich ziplock to keep clean), and sterility doesn't matter much for bleeding control; it's more a concern afterwards. You can fit more for the space that way. Kind of hard to describe, but I found this picture to show the relative size of 2 compressed rolls: http://i30.tinypic.com/w7fpde.jpg