Hearthfire is hitting PS3 next week and I've got a few questions I'd like to ask before I start building my new home(s):

Can you design the house in any way you want to? or would my house look identical to someone else's once I've fully completed it?

Does your Smithing skill increase when building new materials?

How often does your property/properties come under attack?

and lastly..

Once you and your family have settled into one of your new homes, can you pick up and move to one of the other houses at any time? or will your family permanently be locked to the house you had originally chosen? (It would be great if you could tell me which house suits your family best too)

That's all I'd like to know! Thanks in advance

The blueprints/plans are the same. You choose what you want to build however. Stay with a small cottage, or build a great hall and keep the cottage as the entryway. Add an armory, or a library, or a greenhouse. Or don't. Add children's bedrooms. You also choose what decorations and furnishings, but those are standard as well.

You can move your family to other houses.

I'm not sure about the smithing skill, although I would guess it would. So far I've only started building a house with a character that already had smithing maxed.

The attacks don't seem to be that often to me.

I will attempt to respond with what I know. (Fellow PS3 user)

This wasn't answered for various reasons, but yes, your Smithing skill will increase when you build materials for your house.