I've owned all three houses for quite some time and personally, I haven't noticed any major difference in terms of house safety. Lakeview Manor is located near a bandit den and respawning necromancer, Heljarchen Hall is sandwiched between two giant camps, and Windstad Manor is near two Draugr-infested tombs and the Abandoned Shack, but none of these things are really close enough to the houses to have any specific impact on your home. They all have the same Hearthfire-related random enemy spawns, as far as I'm aware.
As for family reactions, here's my experiences from playing with the DLC and trying stuff out:
- Adopted boys like Lakeview Manor and dislike Heljarchen Hall. Not sure about their reaction to Windstad Manor.
- Adopted girls like Lakeview Manor and Heljarchen Hall, but dislike Windstad Manor.
-If you choose to adopt, some spouses (not all\) will gain a dialogue option that you can select that asks them how the children are doing. Certain spouses, like Aela the Huntress and NPCs that share her voice actress, have negative responses to this dialogue at just about every house in the game except Proudspire Manor. Others will have positive reactions to living with kids in your Hearthfire homes, like Ysolda and NPCs that share her voice actress. I believe the same goes for male spouse NPCs. There's no list to go by when it comes to spouses that have this new dialogue and whether they respond negatively or positively, as far as I'm aware. Anyway, the only time they'd ever complain is if you chose to ask them about it, so it doesn't have to be an issue.
Some bugs to take into consideration:
-You can have a wrap-around porch by selecting the appropriate wing options. Sometimes, when building a house, railings won't disappear between porch sections like they should, blocking off porch-access to other wings. The best thing to do is to save before completing the construction of one of these wings to see if this glitch occurred. If it has, soft-reset and try to build it again. It seems completely random.
-Some players experience freezing issues when entering/leaving Hearthfire homes. To prevent this, go to your drafting table and remove the workbenches in your wings, only putting them back when you need them. The freezing seems to be caused by leaving too many of them around your house at one time.
-There's an AI pathing bug at Lakeview Manor involving your spouse when you don't have the Armory wing built, where they'll stand in one spot all day whenever they go outside. If this bothers you, you'll need to forgo the Kitchen or Library wing options and built the Armory wing at that house instead. The other houses don't have this issue.