A fertilized egg does not taste any different, does not have a different consistency, and does not look any different unless you look real close and know what to look for. If you store a fertilized egg at too warm a temperature it will start to develop. I've heard that this can be as low as the upper 70's Fahrenheit but have not experienced that myself. People have been eating fertilized eggs as long as they have kept chickens.
I think this is a great thread discussing multiple roosters. A lot of different experiences from different people.
Managing multiple roosters
https://www.backyardchickens.com/forum/viewtopic.php?id=229968
I'll give my opinion on keeping more than one rooster. If you keep more than one, one of them will be dominant. They determine which one that will be by fighting. Sometimes they resolve the dominance issue without one getting seriously hurt and then form a good partnership taking care of the flock. Sometimes it is a fight to the death. It mainly depends on the personalities of the individual roosters but it can be influenced by different things. If the roosters are raised in the same flock it increases the likelyhood they will work out their differences, whether this is brothers raised in the same brood or a father-son relationship, but it is no guarantee there will not be bloodshed. The hen-rooster ratio has a part to play also. The more hens to share, the more likely they will work it out. There is no magic ratio of hens to roosters where there is a guarantee that there will not be a fight to the death. Same thing with space. The more room you have, the better the odds an accommodation can be worked out, but there is no magic number.
Another potential problem that more roosters can make worse is barebacked hens. When mating occurs, it is not all that unusual or all that bad for the hen to occasionally lose a feather. Whe this gets to the point that bare spots start showing up, it is getting serious and needs to be addressed. If it goes further and the hen gets wounded, it can be fatal. This can be a serious issue. There is no magic number where this is not a potential problem. One poster had 1 rooster with 18 hens and had some barebacked hens. Some roosters have rough techniques and long sharp spurs, so are more likely to injure a hen. Many times a rooster will pick out favorites and give them too much individual attention. A heavy rooster is more likely to cause this problem than a lighter one. Some hens resist the advances of the rooster more than others, especially pullets, so the rooster uses rougher techniques on them. The more roosters you have, the greater the likelihood of this problem. It is usually a lot worse while the roosters are adolescents. Most but not all grow out of this phase.
My personal advice is to keep as few roosters with your hens as you can to achieve your goals. The more hens per rooster, the greater the likelihood of a peaceful content flock and flock owner.
