I'm no expert and maybe some one else can go into more detail but I think breeding crested to crested can result with some of the chicks having vaulted skulls. Also I think breeding crested to crested will result in bigger crests and if your looking for a good free range bird birds having a big...
We had one aggressive rooster at one point but he is gone now. That guy is really friendly though and that is one of the reasons we use him. As far as it being genetic, I'm not entirely sure. I've heard a lot of people say they only use friendly roosters so you won't get aggressive offspring...
redhen where are you located in Southeastern PA? I live in Quakertown and have some swedish growing out right now. I won't be keeping all of them and was planning on putting some for sale soon. An example of two of the guys I have growing out.
I would say hen. At 5 months old a cockeral should problably have a bigger comb and wattles. Although crested SFH roosters tend to have smaller combs. IDK