I think 1077 gave some great advice, not sure why you are out on the forum asking for more... ?
The only thing I will add to this discussion is that it sounds like you need a lot more decor in your tank so these fish can establish territory safely. "A few cichlid rocks" is not going to be enough territory for that many fish in a 46 bowfront tank, I can assure you of that. Any space between 2 solid objects is a territory, any cave or opening is a territory. If things are spaced out and not enough solid pieces or plants divide up the space, each open space is 1 territory that 1 fish is going to claim and defend. Thats what it sounds like is happening, from what I have read here. A cichlid tank, as 1077 has already said, should be heavily "cluttered" to provide plenty of territory.
My contribution to the debate of male/female... I would say the last photo was positively female, the first photo positively male, and the other 2 could be female or sub males, which would account for the fact that they don't quite match up with the obvious male or female. When dealing with most cichlids, there will be 1 dominant male in a tank, no matter how many fish are there... the other males will tend to have less color, be more timid towards that dominant male, or subject of attacks from the dominant male. The same thing somewhat applies with females... if more than one, you will get 1 dominant female... and if she pairs with a male, she can be even more aggressive than he can, especially during spawning.
If you fix the decor/territory situation, the thin fish should have an easier time finding food. Remember that decorating the upper 1/2 of the tank is also important, so either tall plants (live or fake no matter) or something that floats and fills in some space in the upper 1/2 would work well. The more decor you get into the tank the better chance all fish have of finding plenty of food. Also, don't put all of the food in one place at feeding time. Divide up the portion and drop it into 4 places so each fish can target a spot another hasn't claimed. If one fish gobbles its fill and races on to steal another's food... then drop a little more in yet another area near the fish that is having trouble getting to food. You'll have to play with it a little bit til you get a feel for it.
Hope this helps to set you at ease about the info you're getting from 1077. I find it to be very sound and good advice.
Good luck to you!