I've only just got the house in the Pale. It seems to be a bit too close to a giant camp for my liking, so I'm hoping we're still a safe enough distance when the giant and his mammoths respawn. We get a mill with this house, and I still haven't figured out what I'm supposed to do with those things.
Lakeview Manor is the easiest house to get, but it seems to be the most frequently attacked house for me. I get vampires, giants, wolves and mudcrabs, plus there's that alter in the backyard where a necromancer will re-spawn every week or so.
I think the house I buy from Morthal is my favourite one so far. Haven't been attacked there yet. I get a pair of dead draugr lying in the grass, not sure what that's all about, but I hacven't seen any living draugr show up. And the horkers don't seem at all bothered by my housecarl wandering the edges of my land. We also get the fish hatchery so I can farm my own fish, which is a bit more exciting than the apiary.
I haven't adopted any kids yet. I don't think you need to do it at all, the game just tries to guilt-trip you into taking them in when you find homeless kids wandering around the towns with their sob stories. I might adopt kids with my female characters, my males aren't very paternal.
One of my houses has an alchemy tower and enchanting tower, but they seem quite pointless, since you can have those facilities installed in your main hall any way.
But I do love the green house feature. You can plant loads of ingredients, and when they blossom, they attract insects, so that means you get even more free ingredients! Or just keep the bugs as pets if you're that fond of nature.
Oh, and if you're worried about attacks from monsters and wild animals, then having a housecarl, steward and spouse who can fight well should keep your land safe. Wagon drivers may also fend off enemies with an axe if they get too close to the carriage.