One of the biggest issues with GMO food is the allergy cross-over. Because genes from nuts, fish, soy and other highly allergenic plants/animals are used in the to give the need seed the desired characteristics, they can trigger serious allergic reactions in people who had no way of knowing the food was dangerous or even which food it was that caused it! If that wasn't bad enough already, it will certainly only be worse in a grid-down situation where medical care is limited at best.
In a Saturday, May 13, 2017 photo, Kenneth Young, left, and Mark Bowman walk into on the bunkers Vivos is trying to lease in Igloo, S.D. at xFest, a three-day gathering for people who want to convert the site's bunkers, which formerly housed bombs, into shelters for protection against tyranny, anarchy, nuclear war, the end times or any other calamity that might befall civilization. The project is the brainchild of Robert Vicino, a California entrepreneur who has an agreement with a local ranching company to offer 575 of the site's estimated 830 bunkers for lease. (Chris Huber/Rapid City Journal via AP) Chris Huber / Rapid City Journal
For example, have you considered the need for feminine products?  What about canes, walkers, and manually operated wheelchairs?  Pets need food, crates, and toys to keep them occupied while the rest of family members are recovering from chaos.  It will be impossible to cover every contingency but be aware of what those needs are now then prioritize those that you deem most important.
Precious Metals – Investigate this for yourself, but I find the arguments and historical track records against fiat currency and the current rumblings of Government wanting to take care of your investments for you very compelling. Gold is easier to transport with the high cost to weight, but you might have problems cashing a gold coin for a tank of gas. Silver is where I have chosen to invest in precious metals.
It isn't hysteria, and GMO isn't 'evolution'. One of the biggest issues for preppers and survival is that GMO seeds will not reproduce in the same way if the seeds are saved and re-used. In fact, in many instances (maybe all?), it's illegal to save the seeds and re-use them! It's far better to track down heirloom seeds that are native to your area and/or compatible with your climate. A good place to start looking is ×