I'm NEW at this, so take it all with a grain of salt. I haven't had any fighting yet, but I started with a mother and two daughters (and the buck of course). Only two have had kits in colony with only one surviving litter (stupid mom...nothing fighting related). They all snuggle together and look out for each other. Even the buck "keeps an eye" on the kits (if I'm messing with them he comes over and makes sure I've put them all back...it's funny). They are much harder to get hands on (adults) in a colony then in a cage. I have one female that I have no hope of ever grabbing....I'm ok with that...she'll come up to me and sniff my boots, but the second I touch her she takes off. Health is an issue....my colony is indoors, but since everyone is a little harder to get a hold of (if not impossible) forget about doing daily or even weekly hands on health checks.
Turkey has something going on with her dewlap, and thankfully it's minor (she got it wet in the dish and then a bunch of bedding got caked on) but I've had a heck of a time cleaning it up and have to do it little by little as she tolerates it, because unless I want to fight with her I'm not going to be able to pick her up and I can only clean it while she's content and eating.
Because mine are inside my house I don't worry about mites or fleas or worms really. Obviously I still keep an eye out for these sorts of things because they can come in on bedding or hay, but I don't have to worry about anything in the "soil".
I do know that securing an outdoor colony can be extra work to keep it predator proof.
And yes, they definitely breed on THEIR time. I was pretty sure Turkey was going to have a litter, had NO idea that Idjet was pregnant, and I could swear that Grumpy would have had kits two weeks ago (and she still looks like she's going to explode, may have to change her name to Piggy). Thankfully Boyo is a very "take charge" gentleman. He seems to be persistent enough without being OVERLY persistent and annoying to the girls. And it helps that the girls are little hussies....(well, except for Grumpy maybe.)