I see what you're saying. Yes, your definition of a cockeral and a rooster are spot on. However, many people use the term "rooster" when they're really talking about a cockeral. From reading Newbie32's original post and follow up questions, I think this is what's happening. This person doesn't know yet if he/she has boys (cockerals to become roosters) or girls (pullets to become hens) so is trying to figure out what to do. That means they're young birds still and definitely less than a year old, making them really cockerals.
So, in this case, Newbie32 can definitely eat the "roosters" The ideal age, when they're grown out enough but are still tender and good to eat is between 18 and 20 weeks. I've read this age in several reputable sources.
For you and your 28-30 week old cockerals, I personally (and this is a personal opinion) would try them for dinner. If they're not doing you any good as cockerals and they're harmful/annoying/just not nice to you in some way or to the flock, I'd cook them up. I believe that a flock with too many cockerals can (not is, can) be harmful to the flock, if the extra cockerals are by their presence creating conflict with the other cockerals and /or over-mating with the pullets. Plus, you have to spend money to feed them which for many people, is not ideal.
Maybe try to find a recipe that would work for a less tender cut of chicken, like you said, a crock pot or a stew or soup. Or something with a marinade or maybe one where you pound the meat to tenderize it. I use allrecipes.com a lot. I just used this recipe last night for one of my extra cockerals who was 20 weeks old when prep-ed him for dinner. I'm a vegetarian but my husband said it is delicious. I did try it (couldn't resist) and it was good.
http://allrecipes.com/recipe/oven-fried-chicken-iii/
Plus, I believe the chickens we raise taste much better than those we buy at the regular grocery store. Much more flavor. A little chewier and maybe a little more gamey tasting than those bland, tasteless chickens from the grocery store. And my chickens are healthier to eat than the factory farm chickens from the grocery store. Finally, I know what went into raising them and how they were raised so I have a deeper level of respect for the animal that gave it's life for my table.
I learned how to butcher my extra cockerals from following the directions in The Small-Scale Poultry Flock by Harvey Ussery. It has step by step instructions with color pics starting on page 286. It's not that hard to do once you get the hang of it but it is a bit time consuming. And killing the animal is for many of us, me included, the hardest part. I use the broomstick on the ground method, by the way. But, all in, I'm getting better at it, both emotionally and the mechanics of doing all of it, from start to finish.
If you don't cook up your 2 roosters, you may have alternatives, like re-homing them. In my case, this isn't much of an option as I've tried to give my extra cockerals away for free but zero interest or inquiries. Plus, I'm wary anyway of anyone taking them as I would wonder if they're not putting them in a cook pot themselves. I'd rather be the one to eat them if that is to be their fate.
Hope it this is helpful,
Guppy