You can play without food - but it is irritating, and your points are well taken.
[When you get advanced enough, Hero Skill Food Economy 15 (5.1%), plus VIP level 13 (food consumption -12%), plus Resource / Item Week Food Economy, -75%, gives > 100% Food Economy, and so a Food Consumption Rate of 0. i.e. Infinite troops, no food cost.]
In the mean time ...
Join an order - food is 'cheap', your order mates will be able to send you food whenever you need it. It will stick around long enough for you to spend it. Just make to sure to request more than you need, so you have enough while it's draining away. For example, if it shows a -100k/hr rate, ask for an extra 150k in food.
Don't cash in food until you actually need it. For example, if you do a Quest, don't claim it immediately. Doing so often gives a food reward - when you're ready to train or upgrade, claim it then spend it before it disappears on you. Same thing for doing Errands. Since you bought a pack, when you click upgrade with some number in red, you'll be taken to a screen to cash in some rss. Don't cash anything in until you're just about to spend it.
If you're going to sacrifice your troops ...
Help your order mates out - send them as reinforcements to somebody unshielded. (Trap location - your mates will suggest where.) When they get killed, and they will be, your order gets points, and you get rid of some troops. After the fight, the troops will come home - so send them back again. Repeat.
Worst case: dismiss them. Click Council Hall, In the Town tab, click a troop type. Up will come a screen with a slider and a dismiss button.
[I ran into the same thing at first too - I ended up doing a combination of all of the above.]
Plarium: Garbage chest troops are annoying. Would be nice to be able to open the chest and refuse the contents.
Your actually advocating making a purchase and then throwing part of the purchase away? Really?
Also, nothing you've said here saves anyone from a ruined game, Even at level 13 with near max spaces in high level farms and all the other mumbo jumbo i'm still at -380k per hour.
This doesn't even cover the waste of all I gained in boosts and gold trying to upgrade my town.
It's a joke, and our loss.